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Like the images, other non-textual content can also be also provided in separate files and stored in special formats such as chemical structures, gene sequences, or mathematical formulae.

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Images and other files containing non-textual content (collectively "the attachments") are stored in the Attachment Server. Files containing embedded images, as well as mixed mode files, are pre-processed before being loaded to the CLAIMS Direct Patent Database. Links to the attachments are generally referenced in the CLAIMS Direct XML files.

IMG element

The most common way to find embedded/referenced images in the full text of Alexandria XML files is by using the img element.
Depending on the data source, different parameters can be found in this element, including the following most relevant parameters: 

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Drawings section

Attachment refereces references can be embedded in the img element as described above but they can also be in a drawings section of the XML document. Pages published at the end of the original patent document and containing drawings are also referenced in this section.

<drawings mxw-id="PDW3055834" load-source="patent-office">
  <figure num="1">
    <img file="00380001.tif" id="img-00380001" he="228" wi="180" img-format="tif" img-content="dr"/>
  </figure>
</drawings>

A figure id can be used to reference a drawing in the full text as follows:

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USPTO provides chemical structures in ChemDraw (CDX) and MDL (MOL) formats. References to these special files can be found in the attachment element in the chemistry section.

<chemistry id="CHEM-US-00001" num="00001">
  <img id="EMI-C00001" he="19.64mm" wi="54.36mm" file="US07307149-20071211-C00001.TIF" alt="embedded image" img-content="table" img-format="tif"/>
  <attachments>
    <attachment idref="CHEM-US-00001" attachment-type="cdx" file="US07307149-20071211-C00001.CDX"/>
    <attachment idref="CHEM-US-00001" attachment-type="mol" file="US07307149-20071211-C00001.MOL"/>
  </attachments>
</chemistry>

Other sections

In the same way that chemical structures are referenced in the special "chemistry" section, other attachments also have specific elements in the XML files:
sequence-list, math, megatable-doc, and table-external-doc.

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