Item Category Usage: Free

Hi

Want to know significance of Usage Free, know that used in VOV4 , but scenario where this is used , for eg when we define TAN and higher level Item Vcat as TAN the result is TANN.

Also I have searched the usage field in MARD/MARC/MARA, no mention of usage field

Document type OR

Item cat group NORM

Usage FREE

Higher level item category TAN

Default Item category TANN

Regards

Rohit