Size annotations are used to indicate cluster sizes of representative sequences.
A size annotation is specified as a size=N
field in the sequence label. It
may appear anywhere in the label. It must be delimited by
semi-colons, which may optionally be omitted at the end of
a label, though this is not recommended.
You can propagate size
annotations through multiple commands by using the -sizein
and -sizeout options, which are supported by most
(but not all) clustering commands.