It's a signature, "underskriver" lit. translates as "underwriter".
A sign as in sign language is a "tegn" and sign language is "tegnsprog".
I swear the hardest part is trying to fathom what it translates to in English.. in 22 years, I can't recall ever saying "do you sign' :(
The "skriver" in "underskriver" is barely pronounced. I get than Danish people drop a lot of letters from the pronouncing of the word, but still...