The DEBUG_SYMBOL_XXX constants are used for the symbol flags bit-set. The symbol flags describe (in part) a symbol in a symbol group.
The least significant bits of the symbol flags--the bits found in DEBUG_SYMBOL_EXPANSION_LEVEL_MASK--form a number that represents the expansion depth of the symbol within the symbol group. The depth of a child symbol is always one more than the depth of its parent symbol. For example, to find the depth of a symbol whose flags are contained in the variable flags, use the following statement:
depth = flags & DEBUG_SYMBOL_EXPANSION_LEVEL_MASK;
The rest of the symbol flags' bit-set can contain the following bit-flags.