The following explanations are provided to illustrate the use of subfield codes within the 850 tag. They do not reflect the practice of any particular institution with regard to abbreviations, punctuation, and spacing.
Repeatable subfields are designated "(R)".
$a: Library symbol
The $a contains a library symbol, as specified in Symbols of Canadian Libraries. (13) The prefix "Ca" should not be used. This subfield identifies the holding institution to which ILL requests would be directed. For example:
$b: Volumes/issues held (R)
This subfield contains the numerical designations of the volumes and issues held and may also include abbreviations of prefixes to these numbers. AACR2 abbreviations are recommended. Prefixes should be those used in the publication and should not be translated. Numbers must be Arabic and cardinal; Roman numerals and others must be translated. Standard punctuation symbols should be used. For example:
$c: Non-formatted holdings statement
This subfield may include any holdings information except the library symbol. It is used for recording holdings statements if subfield $b (i.e., volumes/issues held) and/or $d (i.e., inclusive dates) cannot be provided. Libraries may use this subfield for existing holdings, but new records should be created using subfields $b and/or $d, if possible. For example:
$d: Inclusive dates (R)
Dates may be used to clarify holdings which are entered in subfield $b, or used in lieu of subfield $b when there is no numbering designation. Dates are given in terms of the Christian era. AACR2 abbreviations are recommended.
$e: Retention statement
Standard abbreviations are given in section "B.3.1: Recommended abbreviations for retention statements". For example:
$g: Volumes/issues lacking (R)
While holdings statements indicate what is held rather than what is missing, a clearer statement may sometimes be made by also identifying missing items. For example:
$h: Dates lacking (R)
The instructions in subfield $g also apply to this subfield.
This subfield contains brief information identifying cumulative indexes that are not given a separate bibliographic record. For example:
$m: Local call number or shelving notation
$n: Copy number
Do not use.
$p: Local system control number
This subfield may be supplied when the local system control number differs from the record control number given in tag 001. For example:
This subfield contains brief free text remarks. It should not be used for strictly local information such as purchase or binding information.
This subfield can be used by a library to specify the location of the reported copy, when this location is not an interlibrary loan center. For example:
$y: Branch sublocation
Used only in conjunction with subfield $x. For example:
The statements below are examples of the subfield coding used in tag 850:
The following are recommendations for the use of abbreviations in the retention statement (i.e., "$e") and for punctuation within holdings statements.
Indicates an unbroken range of holdings from the volume/issue or date specified to the present if the continuing resource is currently being acquired. For example:
Indicates an unbroken range of holdings between the volumes/issues or dates specified if the continuing resource is dead or is not being currently acquired. For example:
Indicates a gap in holdings. For example:
Indicates a non-gap break (e.g., to show discontinuity in the publisher's enumeration/chronology). For example:
Square brackets "[ ]"
Indicate that the volumes or years so enclosed are not complete For example:
Parentheses "( )"
Indicate a significant alternate chronology. For example:
Question mark "?"
Indicates uncertainty. For example:
Forward slash "/"
Connects notations that form a single published physical unit (i.e., a date which covers a single non-calendar year or a combined numbering). For example: