[Flex-help] Problems with "(?r-s:pattern)" rule?

[Georg T. <ge...@te...>]

Hy,

I'm a newbie to flex - great work! On http://flex.sourceforge.net/ I 
found  some documentation on flex mentioning the pattern  
`(?r-s:pattern)' that my system documentation  (man, info on a debian  
sarge, kernel 2.6.20)  doesn't mention?  The rule itself isn't 
recognized either - I tried a (?i:rpt410a). http://flex.sourceforge.net/ 
names the 2.5.33 as the newest release and that is what is installed on 
my system (2.5.33-11) - what is going wrong? Are there different 
flavours of flex with the same version number?

Thanks for your help in advance!

Georg Tenckhoff