J.2 Allowed Replacements of Characters
Syntax
The following replacements 
are allowed for the vertical line, number sign, and quotation mark characters: 
A vertical line character (|) can be replaced 
by an exclamation mark (!) where used as a delimiter.
The number sign characters (#) of a 
based_literal 
can be replaced by colons (:) provided that the replacement is done for 
both occurrences. 
 
The quotation marks (") used as string 
brackets at both ends of a string literal can be replaced by percent 
signs (%) provided that the enclosed sequence of characters contains 
no quotation mark, and provided that both string brackets are replaced. 
Any percent sign within the sequence of characters shall then be doubled 
and each such doubled percent sign is interpreted as a single percent 
sign character value. 
These replacements do not change the meaning of 
the program. 
Ada 2005 and 2012 Editions sponsored in part by Ada-Europe