Offeskeiten isn't German.

What he said. I can't figure out what the putative word could be in German or any of the other usual suspects. the ending -keiten looks German, but yours is as good as anybody's what the offes represents. The -keiten to me looks like the standard German -keit, which forms abstract nouns out of adjectives, e.g., Niedrigkeit 'baseness' < niedrig 'base, lowly'. It's kind of like our -hood (cf. German -heit as in Gesundheit 'health') or -ness. Now it's possible, through strange transcription methods to posit a verb skeiten, which seems more Dutch than German, but that leaves the impossible offes (sounding to mine inner ear a lot like English office). The only place on the Web with offeskeiten is this thread (link). The single example of Offeskeit is a typical Google Books, old words in strange language confuses my OCR.

I also thought for a second it could be Äffischkeit 'apishness', but I got over that. Maybe a nonce word, Auskeit 'outness'. No. Häufigkeit 'frequency, commonness'?

Ceci n'est pas un seing.