The principal Houghton classification schemes – among them, the main Houghton scheme, those for Bibles, Music, Newspapers, Photographically Illustrated Books, and Typ (Printing & Graphic Arts) – are summarized in the Guide to Houghton Classification Schemes.
Houghton classification schemes not summarized in this document include: old Widener classification, B* (Bibliography), and HRR (Houghton Reading Room – obsolete 3/1/2007). For these, see the separate printed schedules kept in the BAL Room.
Some general guidelines about (text borrowed and modified from the larger Guide):
Certain preliminary lower-case letters are to be used before the asterisk and the first letter of the first element of the call number when the size of the book being cataloged falls outside the limits of from 6 to 28 centimeters (top to bottom binding measurement):
f (f AC7)
Use for folio books measuring more than 28 cm.
m (m AC7)
Use for miniature books measuring less than 10 cm.
p (p AC7)
Use for portfolio books measuring more than 46 cm.
Other, less commonly-used designations:
Use for small broadsides.
Use for items in non-standard boxes, e.g. postcards).
Add at the end of the call number for items shelved flat.
Use for large portfolios.
Use for large broadsides.
Use for oversize broadsides.
Use for items shelved in large metal flat file.
*NOTE: For the main Houghton author class, the b to indicate broadsides is applied internally, to the second digit of the first part of the call number (therefore AB85 replaces AC85). For other classification schemes used at Houghton, the b precedes the call number.
NOTE: If by putting an item under 28 cm into a prefab, CMI, or cloth case, if the overall height is increased to over 28 cm, remember to classify the volume as a folio.
Typ size designations:
When required, the call number may be preceded by an f for folio books or pf for portfolio books (note: P was formerly used for PF). Miniature books are preceded by an m; broadsides or flat items by a b, p, or pp, according to size. In subfield c of the 852, these will all be capitalized.