Yes - we decided to include leading zeros. In addition, we added a constraint that validates the ID using the check digit:

matches('[0-9]{9}') and
substring(8,1).toInteger()=
(10-((substring(0,1).toInteger() +
substring(1,1).toInteger()*2 mod 10 +
substring(1,1).toInteger()*2 div 10 +
substring(2,1).toInteger() +
substring(3,1).toInteger()*2 mod 10 +
substring(3,1).toInteger()*2 div 10 +
substring(4,1).toInteger() +
substring(5,1).toInteger()*2 mod 10 +
substring(5,1).toInteger()*2 div 10 +
substring(6,1).toInteger() +
substring(7,1).toInteger()*2 mod 10 +
substring(7,1).toInteger()*2 div 10) mod 10)) mod 10