CUSIP functions return incorrect checksum digit for CINS numbers?

[yanlesin]

In some cases for CINS numbers or CUSIP with character in the middle, function returns incorrectly that identifier is not valid.
Root cause could be that initial CUSIP code was developed with numerical CUSIPs in mind and requires tweaking. Better code could be borrowed from isIsin function, as it handles alpha characters better, but still using the same checksum digit algo

[yanlesin]

small tweak in cpp code was required for correct processing. Now validated CUSIP in whole list and confirm that only PUL and CALLs with invented CUSIP (90 and 95 as issue code) have incorrect checksum digit, which is as expected