Elsewhere it is not there, not in the article and not in the word.
That's at least somewhat debatable. I'd have to run numbers on it, but I'll hypothesize that words ending in -iek are feminine more often (wiek, piek, epiek, republiek, kriek, koliek) than not (giek, um...).
Why debatable instead of demonstrable? The way I was taught, if there is no material distinction, then the purported grammatical distinction has lost its standing.
North Germanic languages acknowledge that f and m have merged and now they only have so-called en-gender and ett-gender, i.e. named after the indefinite articles. In Russian there are no articles, but the gender is seen:
1) in the adjective forms attached to nouns
2) in the endings of nouns (to simplify, а, я for f, о, е for n, and everything else for m)
3) in the declension - distinct declension groups according to gender
4) the related indicative pronouns depend on it
What is the material basis for f and m distinction in Dutch nouns?
You have talked about #4, but this is no better than English hifalutin prose from a century ago where
child was referred to as
it. When this point (relation to pronouns) is alone by itself, it does not have clear grammatical force, but can be seen as a cultural phenomenon, de-personification of children the same way as there is personification of e.g. ships to be referred to as
she.
Many French words can go either way and you just "randomly" assign a gender to indicate that, for example, I am a man saying this about myself (or vice versa).
Nobody ever speaks about the (grammatical) gender of
I. You must be the first one. Or maybe the first one after a Very Long Time.
I have no idea about the school program.
I mean the way common grammar books present it, guidebooks for tourists etc. What is their basis to stating that there is an f and m distinction in Dutch nouns? What practical difference does it make? From what I see, it has similar residual importance like in English or Swedish, certainly no grammatical importance.