Blanket Permit

[jackofalltrades]

I am asking in connection for one of list of documents requirements for H1 Visa and H4 visa at Mumbai Consulate , it mentions the following

This is for H1 Visa
Form I-129 (if Form I-797 is a blanket permit, copy of Form I-797 and I-129), and letter from employer that describes your proposed duties.

This is for H4 Visa
"I-129 (if Form I-797 is a blanket permit, copy of Form I-797 and I-129) of the Principal Applicant, and letter from employer that describes the relationship with the Principal Applicant and the purpose of travel"

Anybody got any ideas?What is Blanket Permit?

[ps0902]

If you are applying for an h1 and h4 visa do not worry about the blanket permit as it is only for L1 visa holder