[semi-extrinsic]

IKEA also frequently use first names (for people), e.g. Billy or Erik, and even abstract words, e.g. Poäng (point, as in "that's a good point".).

As for jf: I searched through the pdf of a 1300 page Norwegian dictionary, and the single word in there containing jf is the abbreviation "jfr." which is the same as the abbreviation "cf." (confer) in English. So jf appears to be a very good choice.

[e12e]

Note that in Norwegian (and, I think, Swedish and Danish) words are joined without a hypen. So anythime a word ending with "j" like "marsj" ("march/marching") is joined with a word beginning with "f" like "fart" ("speed") you'll see "jf": "marsjfart" ("marching speed"/"cruis(e|ing) speed").

Also jfr isn't a particularly rare abbreviations - so ymmv. At any rate, with how words can be combined in Norwegian, there's generally no good safe choice...

Another example, in line with the IKEA theme: "dusjforheng" ("shower curtain").

[semi-extrinsic]

Ah, hadn't thought of that. I had a feeling there had to be more words, but couldn't come up with any off the top of my head. Apparently I write very little Norwegian in vim (I use jk for Esc).

[e12e]

FWIW (again, not sure about rules for joining words in Swedish):

    for abb in jk jf;
    do
      echo "Occurances of ${abb}:"
      grep ${abb} -c \
      /usr/share/dict/{bokmål,nynorsk,british*,svenska}
    done

    Occurances of jk:
    /usr/share/dict/bokmål:90
    /usr/share/dict/nynorsk:39
    /usr/share/dict/british-english-insane:20
    /usr/share/dict/svenska:70
    Occurances of jf:
    /usr/share/dict/bokmål:31
    /usr/share/dict/nynorsk:32
    /usr/share/dict/british-english-insane:0
    /usr/share/dict/svenska:0

So jf seems pretty safe for English, at least. Apart from when adding "jk" to your vimrc …

[auno]

Words are joined the same way in Swedish as described above for Norwegian, so not safe there either.