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. The following labels have valid size annotations:
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.
>KR08766;size=1;>KR08766;size=2
>READ-127;size=5;sample=soil3;
@M141:79:749142:1:1101:14941:1421;size=57721;