I want to know the answer to the following question:
The use of bold fonts and capilization in titles falls under which unusual grammatical distinction?
All the background I'm provided with is that "The rules for which words to capitalise are not based on any grammatically inherent correct/incorrect distinction and are not universally standardized; they are arbitrary and differ between style guides, although in most styles they tend to follow a few strong conventions, as follows:". Is that enough to answer the question?