Merits of Dictionary Catalogue:

a)  Its alphabetical arrangement is easy and simple to use. Anyone knowing the letters of an alphabet and being able to refer a dictionary can find his/her references without any difficulty. 

b)  The works of the same author, different editions of the same title, translations of a work in different languages, all such related entries can be brought together in a dictionary catalogue. This indeed is a great facility for users. 

c)  Subjects that are related but get distributed in a classified catalogue are brought, together in a dictionary catalogue. For 'example, documents on 'roses' with reference to cultivation, decoration, extraction of rose essence for making perfumes and scents, rose garden, rose competition, artificial roses, etc. get distributed in a classified catalogue as they are classified under different classes. But in a dictionary catalogue all these distributed relatives are brought together, making it possible for users to get all the information on roses in one search. These are, in fact, classified pockets in a dictionary catalogue. 

d)  In a dictionary catalogue, subjects are entered under their specific names as such there is no need for a user to know facet relations of subject to use the catalogue. A straight search under a specific heading of a subject would fetch a reader the necessary information. 

e)  New subject headings e.g., artificial intelligence can be inserted in a dictionary catalogue without waiting for any authority list or standard subject headings to incorporate into it. 

f)  All types of relationships between subjects such as hierarchical (broad and narrow terms) associative (related terms), synonyms and homonyms, etc., can be shown in a dictionary catalogue by appropriate cross references.