Based on:

A Based on note is included only on the basis of actual knowledge, not conjecture. No searching is done to determine the work upon which a map is based.

Differs From:

When the bibliographic description for two or more different items would otherwise be identical, a note must be added to explain the differences between the items.

If a statement, such as a pre-copyright registration statement, appears on only one of the items, quote the statement to differentiate between two bibliographic descriptions.

If no suitable quotable statement appears on any of the items concerned, construct a note that describes the situation. Such a "differentiating" note must appear on each of the bibliographic descriptions concerned. Examples:

The presence of a from note, the inclusion of an item in a collection, or the presence of annotations, however, render two or more bibliographic descriptions different and no "differentiating" note is required.

Limitation of Edition:

Statements concerning the limitation of a particular edition of an item are quoted as "edition and history" notes. Example:

Reproduced From:


The bibliographic description of a photographically reproduced reprint-edition photocopy may include a Reproduced from note, in the same manner as the description or a facsimile.

Source of Map:

Many early maps that appear as single maps in LC’s collection may originally have been published as plates bound in another work, usually an atlas. The identification of the atlas or other wok from which a map may have been removed is of potential reference value, and such information may be added to the bibliographic description.

Extreme caution must be used in making this determination, however, since a given map may have been published both as a single sheet and as part of an atlas. Additionally there may be only minute variations in the engraving or coloration of a map plate from one edition of an atlas to another or the same plate may have been used in several successive editions.

Since only a source that can be positively identified is included in a bibliographic description, guidelines in describing the relationship of the map to the source were developed.


Appears In

Anonymous Maps from Magazines, Newspapers, Etc.

Revised Edition

See also: