48 would be diameter of structure. there could be any number of attributes to any number of codes.
we use a decimal because plot codes are seperated by spaces.
so again, MHST -or- MHST.48 would come in on the MHST* layer, and not MH*? how does it know that the "ST.48" after "MH" is not covered by the wild card in desc. key MH*?
If you intend on using the 48 as part of the point description you will need to use a space, the period will not work with description keys. The intent of the wildcard is for additional descriptive information in the point label, as I showed in my screen shot previously using a similar description key with the FD........, anything placed after this must contain a space, this defines its position in reference to the $0 $1 $2 scenario. (i.e. FD*=$0) anything else would be count up from there, so a raw code of FDCIP 1 LS1234 would have a key of FDCIP* and a point description in the key of Found 1" Capped Iron Pipe "LS1234" where 1 inch would be $1 and LS# would be $2.
If you plan on using multiple attributes for a single manhole (I'm assuming your intending to place measurements to inverts), you'll need to define a new point file format the would be comma delimited for the with additional attribuites defined using the Point - User Defined Properties, as additional fields above and beyond your PNEZD so your would need a PNEZDA1A2 etc.....
HTH