alt Hacker News"which nouns are Nouns, and which are just nouns"
English (int al) distinguishes "proper" nouns as a subset of nouns. A proper noun is a name and is capitalized. Hence you might write: King Charles is a king. Now, you also capitalize the first word of a sentence but here King is not the first word of a sentence - King Charles is a name. If you make a small change (indefinite to definite article), you get: King Charles is the King. The second king becomes a moniker and no longer just a description.
English also tends to get capitalization-loopy as soon as religion rocks up (any religion).
You can obviously ignore all that bollocks and write whatever you like, mostly without blushing!
Some other related languages eg German, capitalize all nouns.
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I was being humorous/pithy. I meant e.g. the difference between "property" (the dictionary word) and "property" (the programming word, which is a domain-specific usage of the dictionary word) and "property" (as in Property-Based Testing, an even more domain-specific usage). It's analogous to the concept of regular nouns vs proper nouns, but not the same (which is why I didn't use the term "proper noun").
Maybe this is a joke about the dangers of being abstract going over my head, but I don’t think they literally meant they don’t understand capitalization rules :)