Several fonts have kerning issues. Specifically capital Y and lower case o like in words such as You. The Yo tends to look like Y ou. Lowercase usually looks fine. The request is to be able to find specifically a cap or lower case version of a letter or group of letters. In the Y o example putting a negative tracking on the Y will make it once again look like Yo without having to find and fix in excess of 80 You, yours, etc. per file.