changing the length of a field on bc

we added a custom column on a table and set the column's length to 100. however, on the bc, we only needed our field to be 10 characters. i thought that we'd only have to change the length property on the bc's field, however, unit testing allowed me type 100 chars in that field. did some research and found that a field user prop was required: Text Length Override

name: Text Length Override
value: TRUE