Display path filter with number

Some of my alarms are bit position alarms from an array of integers, so I have paths ending in a number with a bit reference, e.g. .../Alarm1/bit12
If I use a Display path filter of *Alarm1/bit* it shows no matches, however removing the / by using *Alarm1*bit* will work.
It seems like having a number followed by forward slash breaks the search. Is this some sort of special character?