LEFT Function [Visio 2003 SDK Documentation]
Returns the first character or characters in a text string, based on the number of characters you specify.
LEFT(text, [,num_chars_opt])
text The text string that contains the characters you want to extract.
num_chars_opt Optional. The number of characters you want to extract.
Remarks
The value of num_chars_opt must be greater than or equal to zero (0).
If num_chars_opt is greater than the length of the text, LEFT returns all of the text. If num_chars_opt is omitted, it is assumed to be 1.
Example
LEFT ("January 1, 2004", 3)
Returns the value "Jan".