Use case: Collection identifiers in the International Code of Nomenclature for algae, fungi, and plants

[qgroom]

Article 40.7 of the International Code of Nomenclature for algae, fungi, and plants specifically mentions Index Herbariorum as the source of abbreviations to identify collections were types are deposited.

From 1 January 1990 all types for a new name must state where the type is deposited

ICN Article 40

40.7. For the name of a new species or infraspecific taxon published on or after 1 January 1990 of which the type is a specimen or unpublished illustration, the single herbarium, collection, or institution in which the type is conserved must be specified (see also Rec. 40A.5 and 40A.6).

Note 4. Specification of the herbarium, collection, or institution may be made in an abbreviated form, e.g. as given in Index Herbariorum (http://sweetgum.nybg.org/science/ih/) or in the World directory of collections of cultures of microorganisms.

[qgroom]

Also in the International Code of Zoological Nomenclature they say...

Recommendation 73C. Data on the holotype. An author who establishes a new nominal species-group taxon should publish at least the following data concerning the holotype, if they are relevant and known to the author:

73C.6. the collection in which it is situated and any collection number or register number assigned to it;

Recommendation 74D. Choice between syntypes in several collections. When possible, a lectotype should be chosen from syntypes in the collection of a public institution, preferably of the institution containing the largest number of syntypes of the nominal species-group taxon, or containing the collection upon which the author of the nominal species-group taxon worked, or containing the majority of that author's types.

Therefore, collection identifiers are needed for valid typification and knowledge about whether the collection is public or private.