This category contains a set of pages in a particular group. It should only contain individual blue symbols, as well as subcategories and lists of blue symbols. Topics related to the set or an individual blue symbol should be placed in relevant topic categories, such as Category:Symbols.
This is a set category. It should only contain pages that are blue symbols or lists of blue symbols, as well as subcategories containing those things. Topics about blue symbols in general should be placed in relevant topic categories. Categories related to only an individual blue symbol should not be in this category.