@setfield caveats?

What are the @setfield caveats for the 6.5.2 client? Are there any issues with @setfield and R5x and 6.5.2 server? What @setfield code in R5 will NOT work either in 6.5.2 client or server?

I do know that you do not need to declare FIELD:= anymore, but what else?

Subject: @setfield caveats?

I use @SetField intensively - and have upgraded db’s from R4.5 through to 6.5 and have never found a problem

Regards