Scientology fronts: "Division 6C"
Summary
Scientology's Division 6C, to which Narconon International, Criminon International, Applied Scholastics International, The Way To Happiness Foundation, Citizens Commission On Human Rights and many more belong, which are supposedly secular organizations, and whose links to Scientology have been denied by their spokespersons, is to recruit people into Scientology, and to create an 'environment' friendly to Scientology.
Evidences
Church of Scientology International ("CSI") states that Narconon, Criminon, Applied Scholastics (study technology) and The Way To Happiness all fit under "Division 6C." This can be seen in the following fair use excerpts of International Scientology News magazine, issue 27 (2004), p. 20-21:

In the magazine, Division 6C is described as follow:
As can been seen in p. 21 of the magazine, The Way to Happiness, Applied Scholastics (which licenses "study technology" materials), Narconon, and Criminon are all part of Scientology's Division 6C. The real purpose of these Scientology-related organizations is clear when one read the definition of Division 6C CSI provided to the Internal Revenue Service ("IRS") in 1992:
Plainly, from CSI's own words, Scientology's secular fronts are used to recruit new members.
There is another occurrence of Scientology's definition for Division 6C found in a document submitted to the IRS by CSI. In a document titled The Command Channels of Scientology, submitted to the IRS in 1993 as part of CSI's application for religious organization (see it there), which document was also leaked to Wikileaks (much better version), the following definition of Division 6C can be read:
