300 Subfield $f - Type of unit:

Subfield $f contains an indication of the type of unit to which the extent of an item relates. Type of unit includes terms such as page, volumes, boxes, cu. ft., linear ft., etc. that are used to identify the configuration of material and how it is stored. The subfield can assist those keeping statistics on the physical items.

Example:

300 ##$a24$ffile drawers.

Subfield $f is repeatable when alternate or additional forms of extent data are given. Alternate forms of extent data are recorded in parentheses.

Example:

300 ##$a5$fboxes$a(3$flinear ft.)