# Use of subscript cc for HCl and H2SO4

Does the subscript $\ce{X}_{cc}$ mean concentrated? I have never seen this notation. How often is it used and what are the general guidelines to denoting concentrated reagents?

• It is unusual to me. Could you link a reference, or show a picture of it being used? – MaxW Feb 13 '17 at 16:37
• Is this link possibly relevant. It's a long shot for sure, but this has me pretty stumped. In the link it basically uses Xcc where cc means "C Cluster". I still have no idea what the first C means even in this context. – airhuff Feb 13 '17 at 19:30
• A professor used it in a lecture and I'm quite sure he meant concentrated by it. So, it is not really a part of common usage? – waterlemon Feb 17 '17 at 17:37

I found a very old book that used this notation to describe a plot where $X$ many cubic centimeters of $\ce{HCl}$ are added to a solution.