I also found out after this strips original release that in the UK, "slag" is slang for prostitute. I didn't expect that. However, in the world of LWR, "slag" is just as offensive to robots as racial slurs are offensive to humans in the real world. I've always wanted to come up with a slur for robots for the purpose of pointing out racism. Originally, I used the phrase "hunks of junk" but thanks to Sterling we have a better idea.