It would be useful to permit users to define parsers in the patterndb. For example, in our environment, by policy we user a special set and order of characters of our administrators log into hosts and administer them. It would be useful to define a parser of @SYSADMIN@ that would match only our sysadmin accounts. We could then use this parser in the patterndb to take some action such as sending a message to the administrators about the event. Another example would be to create parser for @LOCALIP@ that matches my organizaions IP space. That way a set of rules can be defined using @LOCALIP@ for some kind of alerting, and then any organization could redifine the @LOCALIP@ and use all of the goodness that some third party had created for monitoring logs like an intrusion protection system. Current parsers can be described as QSTRING - match opening char - while not closing char, keep looking ESTRING - while not end string, keep looking NUMBER - while digit keep looking So it seems that general parsers could be constructed with two styles of matching, and then concatenating the together. 1. While in set of characters [some list of characters] 2. While not in set of characters [some list of characters] I would call these INSET to match 1 or more of a set of characters, unless a #-# were specified, then a minimum to a maximum would be required. OUTSET to match 1 or more of anything except the characters, unless a #-# were specified, then a minimum to a maximum would be required. (perhaps a count of + or * could be used to specify 1 or more and 0 or more respectively) and then limit the count of such occurrences so that you could build the @IPv4@ parser as @INSET::123456789*1@@INSET::0123456789:0-2@.@INSET::123456789:1@@INSET::0123456789:0-2@.@INSET::123456789:1@@INSET::0123456789:0-2@.@INSET::123456789:1@@INSET::0123456789:0-2@ and @NUMBER@ would be @INSET::123456789:1@@INSET::0123456789@ @FLOAT@ would be @INSET::0123456789.@ Then a user could make <parser name="THOUSAND">@INSET::,:0-1@@INSET::0123456789:3@</parser> <parser name="MONEY">$@INSET::123456789:1-3@@THOUSAND:::*@.@INSET::0123456789:2@ This is kind of like inventing regular expressions :-( I'm not sure how well this fits into the radix tree matching structure, but I wanted to start this discussion. Given the MONEY example, I think it is obvious that there needs to be a way to specify repeating groups of "something" Let the discussion begin!