Field identifiers are special codes used to search within a certain field of PubMed. Common fields used in broad searches are:
Automatic Term Mapping (ATM)
All Fields [ALL]: Terms that do not map in ATM are searched in all search fields except for Place of Publication, Transliterated Title, Create Date, Completion Date, Entrez Date, MeSH Date, and Modification Date
Medical Subject Headings (MeSH®) or MeSH Terms [MH]
My NCBI retains user information and database preferences to provide customized services for many NCBI databases. It is fully integrated into PubMed: Save searches, organize your search results into collections, create bibliographies, remember previous search histories, and set up alerts for saved searches.