English is not my mother tongue so I'm still learning. I have never heard someone say something like "it allows for". But I am in IT and I keep reading this in a lot of documentation. Every time it makes my head hurts. Sorry but I find it kind of 'stupid'.
I have translated in my mother tongue (French) and I understand the meaning. But it still makes my heard hurts every time I see this. Can someone with a very good English background explain the phrase better?
To allow for a fact or possibility means to include it in your plans or calculations; to permit it to be a part of the situation.
"As it's a holiday weekend I'm going to set off early to allow for traffic congestion."
It's an idiom that spreads through usage. As such, it doesn't need to be particularly meningful on its own; particles rarely are.
Imaginably, this usage is a corruption of "allow for [indirect object, dativ; whom?]", which is perhaps a little bit more natural ("to allow for the police to carry weapons"), which if coinciding with the direct object can be shortend either way ("to allow for the police", "to allow for weapons")--I mean, apparently that's what happened. After all, "für" in German commands accusative, "für wen oder was?" (for who or what) which marks the indirect object; in that sense, your question makes sense; but also cp Sp "por que", Fr "pour-quoi", Ger "wofür" (what for, why), and consider that English has for better or worse substituted, lost or fused cases.
"for" appears in a number of unusual idioms, e.g. the for-infinitive ("(for him to leave) is unimaginable to me", not for me!?). It's the case that particles like of aren't fully lexed. They are just there to fill syntactic positions. Generally, language learners just have to rote learn which prepositions, cases, infinitive constructions, and cetera may be commanded by which verb
