Bag-of-words in CRF++

Question

What is the syntax for a bag-of-words feature in CRF++ template file?

Template example:

#Unigrams
U00:%x[0,0]
U01:%x[0,1]
U02:%x[1,0]

#Bigrams
B

Answer 1

I think it is this way:

#Unigrams
U00:%x[0,0]
U00:%x[0,1]
U00:%x[1,0]

#Bigrams
B

Using the same identifier.