Dear Johnny31,
with all my respect - here's a copy-paste from CIC guidelines:
Note: On your envelope, specify the category under which you are applying and the primary NOC 2011 occupation code you have identified on your application.
AMAH, your can use label provided by CIC itself (your NOC number instead of XXX)
Citizenship and Immigration Canada
Federal Skilled Worker
NOC Category or Arranged Employment Category
Primary NOC 2011 Code: XXXX
Centralized Intake Office
PO BOX 7500
Sydney, NS
B1P 0A9
Canada