http://iscoresports.com/

I have noticed on a few of my printed score book pages that there is a small purple code (C10 / C17 / C6) next to first and/or second base. What is it - what does it mean? Sorry if this has been asked and answered already.

Should be Courtesy Runner... the # next to the C would be the jersey number of the courtesy runner that came in for the original runner.