The backtick forces the previous character to be treated literally. In this case, it means that "a. 3" will match as "verse 3", but "a 3" won't. I wasn't sure if that was appropriate. If you do want "a 3" to match, just remove the backtick, and it will treat the period as optional.
The backtick forces the previous character to be treated literally. In this case, it means that "a. 3" will match as "verse 3", but "a 3" won't. I wasn't sure if that was appropriate. If you do want "a 3" to match, just remove the backtick, and it will treat the period as optional.