String Prefix

The String Prefix character is the apostrophe (').  When prefixed to a value entered into an Excel cell, it signals to the system to store that value as a text string, regardless of whether it looks like a formula or another intrinsic value.  No interpretation of the value is undertaken and the formula is stored as 'entered characters.  The value in the cell is a text string consisting of the charcaters only and not including the string prefix character.