The guidelines recommend using fractions with the Unicode fractional slash in the face value. The example given uses 5⁄144.
I search for a face value of 5⁄144 the results do find the sample item linked in that guidelines section. But when I type in 5/144 in the face value search the results are empty.
I was using 5⁄144 as that is the guidelines example, but the problem also exists with simpler fractions that users are more likely to type.
For example, a search in "Lydia, Kings of" for coins with a face value of "1/24" finds one coin but misses another coin. The missed coin is missed because the editing followed the guidelines and put a face value of "1 Myshemihekte = 1⁄24 Hekte = 7⁄6 Drachm".