What does this dashboard light mean?

I keep getting on and off at various times during the day this idot light coming on it's like this>>> (!)(P) ,I was thinking it could be a malfunctioning parking brake sensor..which by the way I have disconnected about 5 years ago...cause it was jamming on me.... Could it be something else?

CHeck brake master cylinder fluid level.

Thanks LMP..I can't believe that one escaped me... it was lower than low...You know where it's located we tend to avoid checking it... so I hadn't checked the fluid level in over 5 years... sad but true.