The REST API is available at

Content Compare BITS is a very simple REST API with two endpoints: /compare and /authorise.







comparison of two XML files

POST /compare



refresh access token

GET /authorise

POST /compare

Comparisons are posted using multipart/form-data to





Input A to the comparison. We only display the changes in content from this version.

See information below on how to send input files.



Input B to the comparison. We retain the structure of this input in the result file.

See information below on how to send input files.


Use oxygen-tc (default) to get output using Oxygen processing instructions, or html to get a HTML output


To make a comparison you will need to set the Authorization header to use your id as a Bearer token, for example:

Authorization: Bearer eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiIxMjM0NTY3ODkwIiwibmFtZSI6IkpvaG4gRG9lIiwiaWF0IjoxNTE2MjM5MDIyfQ.SflKxwRJSMeKKF2QT4fwpMeJf36POk6yJV_adQssw5c

How to Send Input Files

Files can be sent in two ways: URLs, or as raw XML.

URL inputs
For secure URLs set the Content-Type of the inputA/inputB to text/plain .
Here is an example:

Content-Disposition: form-data; name="inputA"
Content-Type: text/plain

Raw XML inputs
To send raw XML you can send either a raw XML string, or attach an XML file.

Set the Content-Type of the inputA/inputB part to application/xml or text/xml.
Here is an example:

Content-Disposition: form-data; name="inputA"
Content-Type: application/xml

<?xml version="1.0" encoding="UTF-8"?>
<content xmlns:xsi="" xsi:noNamespaceSchemaLocation="">


200 Successful comparison returns the comparison result.

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE book PUBLIC "-//NLM//DTD BITS Book Interchange DTD with OASIS and XHTML Tables v2.0 20151225//EN" "BITS-book2.dtd">
<book dtd-version="2.0">
                        <verse-line>Longior undecimi nobis decimique libelli</verse-line>
                        <verse-line>Artatus labor est et breve rasit opus.</verse-line>
                        <verse-line>Plura legant vacui.</verse-line>
                    <attrib>Martial, xii 5</attrib>
                <label>Chapter 1</label>
                <title>The King of the Wood</title>
                    <title>Artemis and Hippolytus</title>
                <label>Chapter 2</label>
                <title>Sympathetic Magic</title>
                    <title>The Principles of Magic</title>
                <p>In the abridgment I have neither added new matter nor altered the views expressed in the
        last edition; for the evidence which has come to my knowledge in the meantime has on the
        whole served either to confirm my former conclusions or to furnish fresh illustrations of
        old principles. Thus, for example, on the crucial question of the practice of putting kings
        to death either at the end of a fixed period or whenever their health and strength began to
        fail, the body of evidence which points to the wide prevalence of such a custom has been
        considerably augmented in the interval. A striking instance of a limited monarchy of this
        sort is furnished by the powerful mediaeval kingdom of the Khazars in Southern Russia, where
        the kings were liable to be put to death either on the expiry of a set term or whenever some
        public calamity, such as drought, dearth, or defeat in war, seemed to indicate a failure of
        their natural powers. The evidence for the systematic killing of the Khazar kings, drawn
        from the accounts of old Arab travellers, has been collected by me elsewhere.[1] Africa, again, has supplied several fresh examples of a similar practice of
        regicide. Among them the most notable perhaps is the custom formerly observed in Bunyoro of
        choosing every year from a particular clan a mock king, who was supposed to incarnate the
        late king, cohabited with his widows at his temple-tomb, and after reigning for a week was
          strangled.[2] The custom presents a close parallel to the ancient
        Babylonian festival of the Sacaea, at which a mock king was dressed in the royal robes,
        allowed to enjoy the real king’s concubines, and after reigning for five days was
        stripped, scourged, and put to death. That festival in its turn has lately received fresh
        light from certain Assyrian inscriptions,[3] which seem to confirm the
        interpretation which I formerly gave of the festival as a New Year celebration and the
        parent of the Jewish festival of Purim.[4] Other recently discovered
        parallels to the priestly kings of Aricia are African priests and kings who used to be put
        to death at the end of seven or of two years, after being liable in the interval to be
        attacked and killed by a strong man, who thereupon succeeded to the priesthood or the
                <p id="note1">[1] J. G. Frazer, “The Killing of the Khazar
        Kings,” Folk-lore, xxviii. (1917), pp. 382–407.</p>
                <p id="note2">[2] Rev. J. Roscoe, The Soul of Central
          Africa (London, 1922), p. 200. Compare J. G. Frazer, &amp;147;The Mackie Ethnological
        Expedition to Central Africa,” Man, xx. (1920), p. 181.</p>
                <p id="note3">[3] H. Zimmern, Zum babylonischen
          Neujahrsfest (Leipzig, 1918). Compare A. H. Sayce, in Journal of the Royal
          Asiatic Society, July 1921, pp. 440–442.</p>
                <p id="note4">[4]
        The Golden Bough, Part VI. The Scapegoat, pp. 354 sqq., 412
                <p id="note5">[5] P. Amaury Talbot in Journal of the African
          Society, July 1916, pp. 309 sq.; id., in Folk-lore, xxvi. (1916),
        pp. 79 sq.; H. R. Palmer, in Journal of the African Society, July 1912,
        pp. 403, 407 sq.</p>
                <p>J. G. FRAZER.</p>
                <p>1 BRICK COURT, TEMPLE, LONDON, June 1922.</p>
                    <title>The King of the Wood</title>
                <sec sec-type="section">
                    <title>Artemis and Hippolytus</title>
                        <?oxy_insert_start author="deltaxml" timestamp="20220809T134950+0100"?>WHO does not know Turner’s picture of the Golden Bough? The scene, suffused with the golden glow of imagination in which the divine mind of Turner steeped and transfigured even the fairest natural landscape, is a dream-like vision of the little woodland lake of Nemi— “Diana’s Mirror,” as it was called by the ancients. No one who has seen that calm water, lapped in a green hollow of the Alban hills, can ever forget it. The two characteristic Italian villages which slumber on its banks, and the equally Italian palace whose terraced gardens descend steeply to the lake, hardly break the stillness and even the solitariness of the scene. Diana herself might still linger by this lonely shore, still haunt these woodlands wild. 
                        <?oxy_insert_end?>I HAVE said that the Arician legends of Orestes and Hippolytus, though worthless as history, have a certain value in so far as they may help us to understand the worship at Nemi better by comparing it with the ritual and myths of other sanctuaries. We must ask ourselves, Why did the author of these legends pitch upon Orestes and Hippolytus in order to explain Virbius and the King of the Wood? In regard to Orestes, the answer is obvious. He and the image of the Tauric Diana, which could only be appeased with human blood, were dragged in to render intelligible the murderous rule of succession to the Arician priesthood. In regard to Hippolytus the case is not so plain. The manner of his death suggests readily enough a reason for the exclusion of horses from the grove; but this by itself seems hardly enough to account for the identification. We must try to probe deeper by examining the worship as well as the legend or myth of Hippolytus.
                    <p>He had a famous sanctuary at his ancestral home of Troezen, situated on that beautiful,
          almost landlocked bay, where groves of oranges and lemons, with tall cypresses soaring
          like dark spires above the garden of Hesperides, now clothe the strip of fertile shore at
          the foot of the rugged mountains. Across the blue water of the tranquil bay, which it
          shelters from the open sea, rises Poseidon’s sacred island, its peaks veiled in the
          sombre green of the pines. On this fair coast Hippolytus was worshipped. Within his
          sanctuary stood a temple with an ancient image. His service was performed by a priest who
          held office for life; every year a sacrificial festival was held in his honour; and his
          untimely fate was yearly mourned, with weeping and doleful chants, by unwedded maids.
          Youths and maidens dedicated locks of their hair in his temple before marriage. His grave
          existed at Troezen, though the people would not show it. It has been suggested, with great
          plausibility, that in the handsome Hippolytus, beloved of Artemis, cut off in his youthful
          prime, and yearly mourned by damsels, we have one of those mortal lovers of a goddess who
          appear so often in ancient religion, and of whom Adonis is the most familiar type. The
          rivalry of Artemis and Phaedra for the affection of Hippolytus reproduces, it is said,
          under different names, the rivalry of Aphrodite and Proserpine for the love of Adonis, for
          Phaedra is merely a double of Aphrodite. The theory probably does no injustice either to
          Hippolytus or to Artemis. For Artemis was originally a great goddess of fertility, and, on
          the principles of early religion, she who fertilises nature must herself be fertile, and
          to be that she must necessarily have a male consort. On this view, Hippolytus was the
          consort of Artemis at Troezen, and the shorn tresses offered to him by the Troezenian
          youths and maidens before marriage were designed to strengthen his union with the goddess,
          and so to promote the fruitfulness of the earth, of cattle, and of mankind. It is some
          confirmation of this view that within the precinct of Hippolytus at Troezen there were
          worshipped two female powers named Damia and Auxesia, whose connexion with the fertility
          of the ground is unquestionable. When Epidaurus suffered from a dearth, the people, in
          obedience to an oracle, carved images of Damia and Auxesia out of sacred olive wood, and
          no sooner had they done so and set them up than the earth bore fruit again. Moreover, at
          Troezen itself, and apparently within the precinct of Hippolytus, a curious festival of
          stone-throwing was held in honour of these maidens, as the Troezenians called them; and it
          is easy to show that similar customs have been practised in many lands for the express
          purpose of ensuring good crops. In the story of the tragic death of the youthful
          Hippolytus we may discern an analogy with similar tales of other fair but mortal youths
          who paid with their lives for the brief rapture of the love of an immortal goddess. These
          hapless lovers were probably not always mere myths, and the legends which traced their
          spilt blood in the purple bloom of the violet, the scarlet stain of the anemone, or the
          crimson flush of the rose were no idle poetic emblems of youth and beauty fleeting as the
          summer flowers. Such fables contain a deeper philosophy of the relation of the life of man
          to the life of nature—a sad philosophy which gave birth to a tragic practice. What that
          philosophy and that practice were, we shall learn later on.</p>
                <sec sec-type="section">
                    <p>WE can now perhaps understand why the ancients identified Hippolytus, the consort of
          Artemis, with Virbius, who, according to Servius, stood to Diana as Adonis to Venus, or
          Attis to the Mother of the Gods. For Diana, like Artemis, was a goddess of fertility in
          general, and of childbirth in particular. As such she, like her Greek counterpart, needed
          a male partner. That partner, if Servius is right, was Virbius. In his character of the
          founder of the sacred grove and first king of Nemi, Virbius is clearly the mythical
          predecessor or archetype of the line of priests who served Diana under the title of Kings
          of the Wood, and who came, like him, one after the other, to a violent end. It is natural,
          therefore, to conjecture that they stood to the goddess of the grove in the same relation
          in which Virbius stood to her; in short, that the mortal King of the Wood had for his
          queen the woodland Diana herself. If the sacred tree which he guarded with his life was
          supposed, as seems probable, to be her special embodiment, her priest may not only have
          worshipped it as his goddess but embraced it as his wife. There is at least nothing absurd
          in the supposition, since even in the time of Pliny a noble Roman used thus to treat a
          beautiful beech-tree in another sacred grove of Diana on the Alban hills. He embraced it,
          he kissed it, he lay under its shadow, he poured wine on its trunk. Apparently he took the
          tree for the goddess. The custom of physically marrying men and women to trees is still
          practised in India and other parts of the East. Why should it not have obtained in ancient
                    <p>Reviewing the evidence as a whole, we may conclude that the worship of Diana in her
          sacred grove at Nemi was of great importance and immemorial antiquity; that she was
          revered as the goddess of woodlands and of wild creatures, probably also of domestic
          cattle and of the fruits of the earth; that she was believed to bless men and women with
          offspring and to aid mothers in childbed; that her holy fire, tended by chaste virgins,
          burned perpetually in a round temple within the precinct; that associated with her was a
          water-nymph Egeria who discharged one of Diana’s own functions by succouring women in
          travail, and who was popularly supposed to have mated with an old Roman king in the sacred
          grove; further, that Diana of the Wood herself had a male companion Virbius by name, who
          was to her what Adonis was to Venus, or Attis to Cybele; and, lastly, that this mythical
          Virbius was represented in historical times by a line of priests known as Kings of the
          Wood, who regularly perished by the swords of their successors, and whose lives were in a
          manner bound up with a certain tree in the grove, because so long as that tree was
          uninjured they were safe from attack.</p>
                    <p>Clearly these conclusions do not of themselves suffice to explain the peculiar rule of
          succession to the priesthood. But perhaps the survey of a wider field may lead us to think
          that they contain in germ the solution of the problem. To that wider survey we must now
          address ourselves. It will be long and laborious, but may possess something of the
          interest and charm of a voyage of discovery, in which we shall visit many strange foreign
          lands, with strange foreign peoples, and still stranger customs. The wind is in the
          shrouds: we shake out our sails to it, and leave the coast of Italy behind us for a
                    <title>Sympathetic Magic</title>
                <sec sec-type="section">
                    <title>The Principles of Magic</title>
                    <p>IF we analyse the principles of thought on which magic is based, they will probably be
          found to resolve themselves into two: first, that like produces like, or that an effect
          resembles its cause; and, second, that things which have once been in contact with each
          other continue to act on each other at a distance after the physical contact has been
          severed. The former principle may be called the Law of Similarity, the latter the Law of
          Contact or Contagion. From the first of these principles, namely the Law of Similarity,
          the magician infers that he can produce any effect he desires merely by imitating it: from
          the second he infers that whatever he does to a material object will affect equally the
          person with whom the object was once in contact, whether it formed part of his body or
          not. Charms based on the Law of Similarity may be called Homoeopathic or Imitative Magic.
          Charms based on the Law of Contact or Contagion may be called Contagious Magic. To denote
          the first of these branches of magic the term Homoeopathic is perhaps preferable, for the
          alternative term Imitative or Mimetic suggests, if it does not imply, a conscious agent
          who imitates, thereby limiting the scope of magic too narrowly. For the same principles
          which the magician applies in the practice of his art are implicitly believed by him to
          regulate the operations of inanimate nature; in other words, he tacitly assumes that the
          Laws of Similarity and Contact are of universal application and are not limited to human
          actions. In short, magic is a spurious system of natural law as well as a fallacious guide
          of conduct; it is a false science as well as an abortive art. Regarded as a system of
          natural law, that is, as a statement of the rules which determine the sequence of events
          throughout the world, it may be called Theoretical Magic: regarded as a set of precepts
          which human beings observe in order to compass their ends, it may be called Practical
          Magic. At the same time it is to be borne in mind that the primitive magician knows magic
          only on its practical side; he never analyses the mental processes on which his practice
          is based, never reflects on the abstract principles involved in his actions. With him, as
          with the vast majority of men, logic is implicit, not explicit: he reasons just as he
          digests his food in complete ignorance of the intellectual and physiological processes
          which are essential to the one operation and to the other. In short, to him magic is
          always an art, never a science; the very idea of science is lacking in his undeveloped
          mind. It is for the philosophic student to trace the train of thought which underlies the
          magician’s practice; to draw out the few simple threads of which the tangled skein is
          composed; to disengage the abstract principles from their concrete applications; in short,
          to discern the spurious science behind the bastard art.</p>
                    <p>If my analysis of the magician’s logic is correct, its two great principles turn out to
          be merely two different misapplications of the association of ideas. Homoeopathic magic is
          founded on the association of ideas by similarity: contagious magic is founded on the
          association of ideas by contiguity. Homoeopathic magic commits the mistake of assuming
          that things which resemble each other are the same: contagious magic commits the mistake
          of assuming that things which have once been in contact with each other are always in
          contact. But in practice the two branches are often combined; or, to be more exact, while
          homoeopathic or imitative magic may be practised by itself, contagious magic will
          generally be found to involve an application of the homoeopathic or imitative principle.
          Thus generally stated the two things may be a little difficult to grasp, but they will
          readily become intelligible when they are illustrated by particular examples. Both trains
          of thought are in fact extremely simple and elementary. It could hardly be otherwise,
          since they are familiar in the concrete, though certainly not in the abstract, to the
          crude intelligence not only of the savage, but of ignorant and dull-witted people
          everywhere. Both branches of magic, the homoeopathic and the contagious, may conveniently
          be comprehended under the general name of Sympathetic Magic, since both assume that things
          act on each other at a distance through a secret sympathy, the impulse being transmitted
          from one to the other by means of what we may conceive as a kind of invisible ether, not
          unlike that which is postulated by modern science for a precisely similar purpose, namely,
          to explain how things can physically affect each other through a space which appears to be
                    <p>It may be convenient to tabulate as follows the branches of magic according to the laws
          of thought which underlie them: </p>
                Sympathetic Magic
                (Law of Sympathy)
         |                             |
 Homoeopathic Magic             Contagious Magic
 (Law of Similarity)            (Law of Contact)
                        <graphic xmlns:xlink="" xlink:href="magicbranches.svg" mimetype="image/svg-xml"> </graphic>
                    <p>I will now illustrate these two great branches of sympathetic magic by examples,
          beginning with homoeopathic magic.</p>

GET /authorise

Get updated token information by using your refresh, id, and expiry information you downloaded earlier by passing them as query parameters to /authorise, for example:


The response will be in the same JSON format you received when you requested your token.


400 Bad Request. Check the error message for details of what may need to be changed when you re-attempt the comparison. If you continue to receive an error, please contact support using our Customer Support Portal and report the error details.

500 Server Error. If you encounter these, please contact support using our Customer Support Portal and report the error details.

Errors will be reported with a parent element of <error> containing these child elements:

  • <errorMessage> - description of the error

  • <errorId> - unique ID to track errors

  • <errorCode> - the HTTP Response code

  • <timestamp> - ISO 8601 timestamp

An example of an error:

    <errorMessage>Parameter output-type value is invalid. Please choose from oxygen-tc or BITS(default)</errorMessage>


Only BITS content can be compared. Files will be rejected by the API if they do not conform and you will receive an error.

If you’re getting an error message blocking your BITS content from being compared, please contact DeltaXML.

Usage Limit

Trial users get 100 comparisons / month.

Paid subscribers get 1000 comparisons / month. To request more, please contact DeltaXML.

To see your current usage, go to Subscription Manager in MyDelta and find the relevant deal. Under the “Quantity” column will be information on your current usage level.

Input Size Limit

There is an input size limit of 5 Mb for each input file for trial users.

Ready to Subscribe?

If you’re ready to subscribe to Content Compare BITS, please contact DeltaXML.