Tips for Golfing in BBC BASIC What general tips do you have for golfing in BBC BASIC? I'm looking for ideas that can be applied to code golf problems in general that are at least somewhat specific to BBC BASIC (e.g. "remove comments" is not an answer).
Spaces after keywords are optional because of tokenisation. For example:

INPUT answer$
PRINT answer$
IF answer$ = 'Hi' THEN
  PRINT 'Hi!'
ENDIF


Can be shortened to

INPUTanswer$
PRINTanswer$
IFanswer$='Hi'THEN
  PRINT'Hi!'
ENDIF


The corollary of this is, a variable name cannot start with a keyword. So PRINTa is not a valid variable name. However printa is.

Spaces before keywords can be more tricky. Variable names can end with a keyword, so if variable name and keyword are run together they will be interpreted as a variable name.

For example the following gives a "no such variable" error because the variable aPRINT is not defined:

  a=7
  IF7=aPRINT"seven"


By rearranging this can be avoided:

  a=7
  IFa=7PRINT"seven"


This is a trivial example, but frequently rearranging an expression to end in a number or bracket instead of a variable name will enable you to eliminate a trailing space.