The file containing the list of blocklists is /var/ipfire/ipblocklist/sources. The explanation of the fields in the file is in the file header, so it’s easy enough to add new entries if you want, however the file will be overwritten by any future updates.
If you find any lists which would be useful to other people you could submit a patch to update this file, but before doing this it’s important to check that you’ve got the maximum frequency of checking for updates right, as many lists will block anyone trying to update too often. If you’re going to submit a patch it’s also important to check that the licence for the lists allows the list to be included in the ipfire distribution.
Possibly in a future update we can allow the possibility of a sources.local file, but I think the feature needs to be left as it is for a while before adding new functionality.
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