A dictionary is a list of the words, phrases, file names, and the file name extensions that pertain to a specific topic. When a dictionary is part of a content filtering policy condition, Symantec Messaging Gateway searches your email messages for the contents of the dictionary. If you configure Symantec Messaging Gateway to scan non-plain text file attachments, they too are scanned for contents of the dictionary.
Content filtering policies evaluate matches to a referenced dictionary with substring text analysis, not regular expression analysis. When a substring in a message matches a dictionary entry, Symantec Messaging Gateway takes the actions that you specify in the policy.
The types of dictionaries that you can use are as follows:
Premium dictionaries and custom dictionaries
Most of the premium dictionaries and custom dictionaries that Symantec Messaging Gateway provides already contain predefined words, phrases, and characters. You can view the contents of the premium dictionaries and custom dictionaries, enable and disable existing keywords, and add words, phrases, or characters.
Examine the contents of the premium dictionaries and custom dictionaries before you use them to determine if they meet your needs. If they do not, you can add the new user-defined words and phrases that you need. You can also disable the predefined words and phrases that you do not want to use.
Some premium dictionaries and custom dictionaries are empty. You must populate them with user-defined words or phrases before you can use them in a content filtering policy.
The dictionaries that are marked as ambiguous (such as Profanity (ambiguous)) contain the terms that can be legitimate when used in certain contexts.
In addition to premium dictionaries and custom dictionaries, you can create user-defined dictionaries. You populate user-defined dictionaries to suit a site-specific or business need. These dictionaries must contain at least one word or phrase.