seq Sequence Number
Sequence number of a document within the type of sequence named by the element to which this attribute is attached: on a <volume> element, the sequence within the volume; on an <issue> element, the sequence within the issue; on an <fpage> element, the sequence within a single page; and on an <elocation-id> element, the electronic sequence.
OPTIONAL on many elements; click for list and usage
|Text, numbers, or special characters||The number of the document in a sequence of documents within a volume, issue, electronic compilation, or even on the same page.|
|Restriction||This attribute is an optional attribute; there is no default.|