This is the language reference category.
“Sum-class symbols, or accumulation symbols, are symbols whose sub- and superscripts appear...Sum-class symbol
“The preamble is the first section of an input file, before the text of the document itself, in...LaTeX preamble
“A LaTeX environment is one of the following: Text inside a float environment is "floated...List of LaTeX environments
This category has the following 3 subcategories, out of 3 total.