CLUSTAL format, in which each sequence and its name are on the same line and the sequences can be partitioned into a number of blocks separated by empty lines. The word "CLUSTAL" indicating the format can begin in the first line, but such a first line is optional.
CLUSTAL format Example:
seq0
FQTWEEFSRAAEKLYLADPMKVRVVLKYRHVDGNLCIKVTDDLVC
seq1 -------KYRTWEEFTRAAEKLYQADPMKVRVVLKY----RHCDG
seq2 EEYQTWEEFARAAEKLYLTDPMKVRVVLKYRHCDGNLCMKVTDDA
seq0 LVYRTDQAQDVKKIEKF
seq1 NLCIKVTDDV-------
seq2 VCLQYKTDQAQDVKK--