FWIW (again, not sure about rules for joining words in Swedish): for abb in jk j...

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 …