300 Subfield $a - Extent:
Subfield $a contains the extent of the item, that usually consists of the number of physical pages, volumes, total playing time, etc., of each type of unit. For multipart and serial items, it includes volumes (and pagination when pages are numbered consecutively).
In records formulated according to ISBD principles, subfield $a contains all data up to and including the next mark of ISBD punctuation [e.g., a colon ( : ), a semicolon ( ; ), a plus sign ( + )].
Examples:
300 ## $a149 p. ;$c23 cm.
300 ## $a1 score (16 p.) ;$c29 cm.
300 ## $a11 v. :$bill. ;$c24 cm.
300 ## $a1 map :$bcol. ;$c30 x 55 cm.
300 ## $a1 sound disc (20 min.) :$banalog, 33 1/3 rpm, stereo. ;$c12 in.
300 ## $a160 slides :$bcol. ;$c2 x 2 in.
300 ## $a8 reels of 8 (7557 ft.) :$bsd., col. ;$c35 mm.$3dupe neg nitrate (copy 2).
300 ## $a1 videocassette of 1 (Beta) (30 min.) :$bsd., col. ;$c1/2 in.$3(2 copies)
300 ## $a1 computer disk :$bsd., col. ;$c3 1/2 in.
300 ## $a95 linear ft.
300 ## $a10 boxes (24 linear ft.)
When the statement of pagination and of illustrative matter are combined, they are both recorded in a single subfield $a.
Examples:
300 ## $a74 p. of ill., 15 p. ;$c28 cm.
300 ## $a27 leaves of plates, 4 p. ;$c31 cm.
In works that are not yet complete, only the type of unit designation is recorded preceded by three spaces. (The actual number of pieces received may be recorded as temporary data enclosed in angle brackets.)
Examples:
300 ## $a v. ; $c29 cm.
300 ## $av. <1-3 > ;$c25 cm.
For mixed materials, terms in the physical description indicating the type of unit may be separately subfield coded (see description of subfield $f). In these cases, subfield $a contains only the numeric extent designation.
Examples:
300 ## $a42$fcu. ft.
300 ## $3poems$a1$fpage :$c108 cm. x 34.5 cm.
Subfield $a is repeatable when alternate or additional forms of extent data are given. Alternate forms of extent data are recorded in parentheses.
Examples:
300 ## $adiary$a1$fvolume$a(463$fpages) ;$c17 cm. x 34.5 cm.
300 ## $a17$fboxes$a(7$flinear ft.)
[Repeated subfield $a for archival materials.]
Field 300 may be repeated to describe different parts of multipart items.
Examples:
300 ## $a1 reel (312 ft.) :$bsi., b&w ;$c16 mm.$3ref print.
300 ## $a1 reel (312 ft.) :$bsi., b&w ;$c16 mm.$3dupe neg.
[Repeated field in a record for motion pictures.]
300 ## $a65 prints :$brelief process ;$c29 x 22 cm.
300 ## $a8 albums (550 photoprints) ;$c51 x 46 cm. or smaller.
[Repeated field in a record for graphic materials.]
For music, subfield $a is repeated for parts information when a subfield $b or $c separates it from the main extent data.
Example:
300 ## $a1 score (30 p.) ;$c20 cm. +$a16 parts ;$c32 cm.
To return, select: