code: def excludeFromDB(abbr = None, dbname = manualDBname):
      
      dbLoc = os.path.normpath(os.path.dirname(__file__))
      with dbm.dumb.open(dbLoc + '/' + dbname) as db:
          if isinstance(abbr, str):
              db[abbr] = ''
          elif isinstance(abbr, list) or isinstance(abbr, tuple):
              try:
                  db.update({k : '' for k in abbr})
              except TypeError:
                  raise TypeError("The keys and values of abbr must be strings.")
          elif abbr is None:
              pass
          else:
              raise TypeError("abbr must be a str, list or tuple.")
docs: Marks _abbr_ to be excluded the database of journals. The database is kept separate from the one scraped from WOS, this supersedes it. The database by default is stored with the WOS one and the name is given by `metaknowledge.journalAbbreviations.manualDBname`. To create an empty database run [addToDB()](#metaknowledge.journalAbbreviations.backend.addToDB) without an _abbr_ argument.
  
      # Parameters
  
      _abbr_ : `optional [str or tuple[str] or list[str]`
  
      > The journal abbreviation to be excluded from the database, it can either be a single string in which case that string will be exclude or a list/tuple of strings can be given with the abbreviations.
  
      _dbname_ : `optional [str]`
  
      > The name of the database file, default is `metaknowledge.journalAbbreviations.manualDBname`.