440 Subfield $p - Name of part/section of a work:

Subfield $p contains a name designation of a part or section of a series title.

Examples:

440 #0$aActa Universitatis Stockholmiensis.$pStockholm economic studies ;$vnew ser., 7

440 #0$aJanua linguarum.$pSeries maior,$x0075-3114 ;$v100