Module 30.12. Physical description (field 300)

30.12.1. Extent of item

For current serials, the extent of item (subfield $a) contains only the specific material designation (SMD) for the type of electronic resource, as given in AACR2 9.5B. The Library of Congress is applying the optional provision of the rule to give conventional terminology for the specific format of the physical carrier.

AACR2 9.5B1	Optional provision
300 ## $a computer optical discs	300 ## $a CD-ROMs
300 ## $a computer optical discs	300 ## $a DVD-ROMs
300 ## $a computer disks	300 ## $a diskettes
300 ## $a computer disks	300 ## $a floppy disks
300 ## $a computer tape reels	300 ## $a tape reels
300 ## $a computer tape cartridges	300 ## $a tape cartridges

30.12.2. Other physical details

Give physical characteristics, generally only concerning sound and color, in subfield $b (AACR2 9.5C). If the electronic resource produces sound, give "sd."; if the electronic resource, not just the title screen, is encoded to display in two or more colors, give "col."

300 ## $a CD-ROMs : $b col.

Give other physical characteristics information concerning the number of sides used, recording density, and sectoring, if considered important (AACR2 9.5C2).

300 ## $a computer disks : $b sd., col., single sided, single density, soft sectored

300 ## $a tape reels : $b 6250 bpi

30.12.3. Dimensions

Give the diameter of the disc (or disk) in inches to the next highest 1/4 inch in subfield $c, as specified in AACR2 9.5D. (9.5D1 gives the option to give the dimensions in centimetres; as of Fall 2002, LC is not applying this option.)

CD-ROMs:

300 ## $a CD-ROMs ; $c 4 3/4 in.

Floppy disks:

300 ## $a computer disks ; $c 5 1/4 in.

If the dimensions of the floppy disks change over the course of the publication, or if the publisher issues more than one size of disk to accommodate different disk drive sizes, give the lesser size followed by the greater.

300 ## $a floppy disks ; $c 3 1/2-5 1/4 in.

No dimensions are given for magnetic tape reels, according to AACR2 9.5D1.

30.12.4. Accompanying material

Accompanying material consists of two general types, documentation (e.g., user's guides, manuals, etc.) and search and retrieval software. If it accompanies each issue, record the information in subfield $e.

300 ## $a computer disks ; $c 5 1/4 in. + $e technical documentation

When accompanying material does not accompany each issue, or it is unclear whether or not it does, a note may be given in field 500 or 556 , as appropriate (see CCM 30.14.7).