A lot of C++ code uses syntactical conventions for marking up member variables. Common examples include
You have to be careful with using a leading underscore. A leading underscore before a capital letter in a word is reserved. For example:
are all reserved words while
are not. There are other situations where leading underscores before lowercase letters are not allowed. In my specific case, I found the _L happened to be reserved by Visual C++ 2005 and the clash created some unexpected results.
I am on the fence about how useful it is to mark up local variables.
Here is a link about which identifiers are reserved: http://stackoverflow.com/questions/228783/what-are-the-rules-about-using-an-underscore-in-a-c-identifier