AFAIK they're reserved by VFP, and it's the same in 6.0, the "m" is used to make a distinction between a memory variable and a fieldname with the same name.

>hi, every body
>I meet a strange problem in VFP 7.I declare a Class using
>

set classlib to myclass
>store createobject ("myclass") to a
>

>but when I launch a Method in the class
>

>a.GetSqlData("Select * from txl order by name","temp")
>

>I always get a error message "Syntax Error"
>If I change the variable 'a' to 'a1' and launch
>

>a1.GetSqLData("......")
>

>I can get what I need.
>A summary below is which single letter can't use:
>

>a,b,c,....j and m
>

>
>when I use 'm' as variable, I get another error message "File 'getsqldata.prg' doesnt exist"
>
>I have never met this question in VFP 5/6 , Anybody has some idea?
>
>TIA, Have a nice day!