of course, you can label anything anything, so maybe my stetement should have been

"to make someththing that will be accepted throughout the industry as a PLC you need to make it programmable in ladder logic."

Erik

re abbreviations:
My knowledge of PLCs come from applying for a job (which I got) by mistake. I went to the interview to talk about "Programmable Logic Chips" and we actually talked in the interview for quite a while before it was realized that we talked about two different things. example Q:"how much programming have you done" A:"lots"