The Z80 has a relative jump. Teenage me was loading a hand-assembled search function as an initialised array of integers in Basic, and relative jumps didn't need to be adjusted for the load location, which reduced the amount of post-load adjusting of addresses. It was +100x faster than Basic, just a straight scan.
jr?
yes, that looks like the one. I think I was using the conditional jump, so it could have been djnz, but I think it was jr. 1 byte jump offset, and I recall my little function bumping against that limit - I might have re-arranged it. http://z80-heaven.wikidot.com/instructions-set:jr