I think RA is mistaken. All Gypsy or Traveller languages in this day and age, were once pure languages, but are now diffused with other influences. The main one in the UK of course is English, so we talk in terms on Anglo Romany today. The languages are interchangeable so Cant (Gypsy folk call it barrow boy talk) taken from street talk, is mixed with Shelta, Gammon, and modern slang. I do not believe that this devalues the language in it's current use, any more that our beautiful regional accents and dialect devalues the English language. If slang is an unacceptable word then maybe colloquialism may replace any missing respect.