Field name changes when I add a number

Question

I use the shortest words possible when creating fields in a custom list. I go back and rename it sometimes, but the URL retains the shorter name.

I have created a list, and have fields IS1 thru IS10. If I name the column I or IS, the internal field name matches, but when I add the number, it changes the I.

This is what I see for IS5: Field=%5Fx0049%5FS5

I also created a field for I and IS for comparison:

I: Field=I

IS: Field=IS

Can anyone explain why it would do this?

Answer 1

Not exactly sure as to the why but I was able to duplicate your issue. A similar thing happens when you name a Field names with special characters. "For e.g. trying to create field Emp Name gives internal name as Emp_x0020_Name." Whatever the reason, it appears to be deliberate and possibly a security measure.

Field Name Internal Name AA AA A5 %5Fx0041%5F5 AA5 %5Fx0041%5FA5 AAA5 %5Fx0041%5FAA5 AAAA5 AAAA5 II II I5 %5Fx0049%5F5 II5 %5Fx0049%5FI5 III5 %5Fx0049%5FII5 IIII5 IIII5