explicit laws about whitespace in rules

I'd like to know where EXACTLY whitespace is permitted in rules.  Is it 
legal to write

   \c [CHARACTER NAME]

or must I write

   \c[CHARACTER NAME]

-- 
Jeff "japhy" Pinyan         %  How can we ever be the sold short or
RPI Acacia Brother #734     %  the cheated, we who for every service
http://japhy.perlmonk.org/  %  have long ago been overpaid?
http://www.perlmonks.org/   %    -- Meister Eckhart

• explicit laws about whitespace in rules by Jeff 'japhy' Pinyan
• Re: explicit laws about whitespace in rules by Damian Conway