Learn English – Should “Applied Cryptography” be capitalized? Is it a proper noun

"Hell" is capitalized when it is used as a proper noun. That is, you capitalize it when you are referring to it as a specific place. However, it can be perfectly legitimate to leave it uncapitalized if you are not referring to a specific place.

"That job was hell" does not refer to a specific location, but rather a nebulous concept of torture. Thus, it is not capitalized in this sentence.

It's important to understand what a "proper noun" is. Basically, it's an identifier for a specific person ("Fred"), place ("Paris"), or entity ("United Nations").

"Person" and "place" are fairly easy to understand, but "entity" can get a little confusing. You could, in theory, have a committee for "health professional services" (whatever that is) without ever assigning it a formal name (it might simply be referred to as "the committee chaired by Frank Jones"). In this case there is no "proper noun" to identify the committee. Or you might decide to name it the "Wednesday Afternoon Caucus" (for some screwy historical reason), or you might actually choose "Health Professional Services Committee".

Having chosen a name, you might, in some protracted texts, want to give the committee a "nickname" (just as "John Smith" is perversely nicknamed "Jack"). In most cases the chosen "nickname" is either an acronym ("HPSC") or some shortened form of the formal name (eg, "Services Committee" or simply "Committee"). As with human nicknames, organizational nicknames are treated as proper nouns and capitalized.

But with a "nickname" such as "Committee", however, one needs to be careful to distinguish between the use of the word as a nickname and the use of the word as a generic reference. Eg, if there is a separate "advisory committee", that is typically a generic reference, even though "Committee" is being used in the document as a nickname for the HPSC. In this case using upper and lower case properly helps distinguish which meaning is intended.