org: Custom searches

 
 4.8 Custom Searches
 ===================
 
 The default mechanism for creating search strings and for doing the
 actual search related to a file link may not work correctly in all
 cases.  For example, BibTeX database files have many entries like
 ‘year="1993"’ which would not result in good search strings, because the
 only unique identification for a BibTeX entry is the citation key.
 
    If you come across such a problem, you can write custom functions to
 set the right search string for a particular file type, and to do the
 search for the string in the file.  Using ‘add-hook’, these functions
 need to be added to the hook variables
 ‘org-create-file-search-functions’ and
 ‘org-execute-file-search-functions’.  See the docstring for these
 variables for more information.  Org actually uses this mechanism for
 BibTeX database files, and you can use the corresponding code as an
 implementation example.  See the file ‘org-bibtex.el’.