Some tags will use an @xml:id to refer to a single, specific element. For example, if we 'declare' in the <teiHeader> that Samuel Beckett is the author of the transcribed work by typing:
[xml]
<author xml:id="SB">
<name>Samuel Beckett</name>
</author>[/xml]
the computer will know that every time we mention the initials "SB" as an attribute's value, we are referring to Samuel Beckett. To connect these initials back to the @xml:id, they have to be preceded by a hashtag (#). For example:
[xml]
<del hand="#SB"> = CORRECT
<del hand="SB"> = INCORRECT[/xml]
Formal requirements:
For this system to work, every @xml:id has to be unique (no two occurrences in the same XML-document), and has to start with a letter. For example:
[xml]
<seg xml:id="qdfjkls"> = CORRECT
<seg xml:id="1qfqdfjk"> = INCORRECT[/xml]
The length of the @xml:id may vary. Also, please do not use any spaces, and only use standard (ASCII) letters (a-z; A-Z), numbers (0-9), underscores (_) or dashes (–).
While XML syntax demands @xml:ids to be unique in the document, the BDMP's cross-document functionalities require @xml:ids to be unique across the entire module. A good way to achieve this is to start each value with a short code for the current document, such as 'ts1', 'ms1', 'ts2', and so on, followed by a random string of characters.