HowTo:Manage your variables

The requirements page for the POV-Ray Object Collection has some good tips:

Variable names exposed to the user should also be prefixed with the contribution name or the unique prefix and should be directly followed by an underscore ('_'). This includes named objects, textures, pigments, normals etc. For example the 'Netball' object exposes the NB_BallRadius variable to enable the radius of the ball to be controlled. You may use the #local directive to define variables with a local context within macros etc., in which case you are not obliged to adhere to this naming standard within those macros, because the local context should avoid naming conflicts.