Although the Aruduino environment supports the ternary "Conditional Operator", there is NO mention of it in ANY of the online documentation. There should be an a additional heading on the language reference page:
"Conditional Operator" "? : (ternary operator)"
With appropriate explanation so that newbies can discover it's usefulness.
The doc on 'variables' should mention what VALUE is set for "HIGH" and "LOW" and that it requires an INT type, not boolean, which is what one would assume for a two state "type".
The 'integer constants" needs to make it clear that "0" is not "O". eg. "Leading ZERO, not Oh." Logically one would think that with B for binary, and X for heX, that OH would be the prefix for Octal.
The business of case sensitivity for the prefixes and suffixes on var types should also be addressed.
It would also be extremely useful if the B operator worked for more than 8 bits. One should be able to specify a int or long with binary notation too. The AVR assembler supports insertion of underscores "_" in a binary constant to make it easier to group the bits. Why not add this to Arduino?
The data type 'array' needs to have an example of how to use multiple lines to initialize a long or multidimensional array.