Can't search for "Aั" in lettering; Can't search for Thai vowel sign Mai HanAkat

Searching with a filter of “Aั” in Lettering (“A" followed by the Thai vowel sign Mai Han-Akat) finds no results, but I know it is used in the Reverse lettering of N#319308 .

Searching for Thai vowel sign Mai Han-Akat as a general search returned no results, even though it is used. Searching in lettering doesn't find all uses.

(Searching for just the vowel sign in lettering returned only one result, N#11591 . Probably because the vowel was after a quote mark and not a letter in that case. I've submitted a change request to remove that vowel..)

Hello,
This is not a bug, but the intended behaviour: the filed “lettering” looks for full words. As pointed our by rsirian1, you can use the wild card “*” to search for partial words (or even a single letter).
Example: https://en.numista.com/catalogue/index.php?r=&ct=coin&im1=&im2=&tb=y&tc=y&tn=y&tt=y&tp=y&ru=&ca=3&no=&v=&i=*A%E0%B8%B1*&b=&ie=&u=&a=&dg=&m=&f=&t=&w=&mt=&g=&se=&d=&c=&wi=&sw=

Or https://en.numista.com/catalogue/index.php?r=&ct=coin&im1=&im2=&tb=y&tc=y&tn=y&tt=y&tp=y&ru=&ca=3&no=&v=&i=*%E0%B8%B1*&b=&ie=&u=&a=&dg=&m=&f=&t=&w=&mt=&g=&se=&d=&c=&wi=&sw=