These are the built-in IPL variable data types.

identifier    size    description
----------    ----    -----------
bool          1       true/false (1/0)
byte          1       ordinal number (0..255)
short         1       ordinal number (-128..127)
word          2       ordinal number (0..65535)
int           2       ordinal number (-32768..32767)
long          4       ordinal number (-2147483648..2147483647)
real          6       extended number (2.9^-39..1.7^38)
str           256     an array of characters (1-255), str#0 = length of str
file          n/a     used as a file handle reference only

A strings length cant be limited by doing "str<byte>"
example: @str<4> usrname    would only allow a name of 4 characters