If you're going to do that then please be considerate enough to add links to the other places you cross posted. This will let us avoid wasting time due to duplicate effort and also help others who have the same questions and find your post to discover all the relevant information. When you post links please always use the chain links icon on the toolbar to make them clickable.
This really just comes down to poor programming practices on the part of the library author.
First of all, the C++ specification states that all identifiers that start with an underscore followed by an uppercase letter are reserved.
Second, the C++ specification states that all identifiers that start with an underscore are reserved for use in the global namespace.
Third, use descriptive variable names!!! Not only will this make the code much easier to understand, it also makes name collisions less likely.