http://tools.ietf.org/html/rfc5424#section-6
ABNF for 5424 indicates all are valid, which makes sense given the range of 
8 * (0 - 23) + 7

This was another change aimed at reflexivity initially, but it might be easier to just remove support for it entirely.  I simply noticed it was being inserted in addition to the creation derived from facility/severity, and thus breaking a parse/produce/parse loop on a given input.