- either by its text ID, or its index in an associated alignment.
- Normally, sequence features are associated with sequences rather than
- alignments, and the sequenceIndex field is given as "-1". In
- order to specify a sequence by its index in a particular alignment,
- the sequenceId should be given as "ID_NOT_SPECIFIED",
- otherwise the sequenceId field will be used in preference to the
- sequenceIndex field.
+ either by its text ID, or its index (base 0) in an associated
+ alignment. Normally, sequence features are associated with sequences
+ rather than alignments, and the sequenceIndex field is given as
+ "-1". In order to specify a sequence by its index in a
+ particular alignment, the sequenceId should be given as
+ "ID_NOT_SPECIFIED", otherwise the sequenceId field will be
+ used in preference to the sequenceIndex field.