What’s appropriate documentation?
In order to guard against showing favoritism for third party products, editors for the documentation system need to consciously consider whether the goal of a given document is to provide useful information to an end user in the form of a how-to or tutorial, or if it is more of a marketing-type document.
These decisions should be made on a document-by-document basis, and our guiding concern should be whether or not the document will be found by the people who need it. (Content that tends to being advertising for a commercial product, rather than documentation, should always be declined.) The position of the Plone Foundation has always been that commercial add-on products for Plone that respect the GPL (eg, Enfold products) are perfectly permissible to be listed on plone.org/products and there is no reason that they can't also be documented on plone.org.
The big difference between documentation in a product's own section and docs in the documentation section is their inclusion in the topical listings. Both are searchable from the Documentation search.
Some documentation clearly belongs in the product's own documentation section. For example, the PloneFormGen how-tos, which clearly cover PFG issues. Folks who need these will be searching with the term “PloneFormGen,” and will find what they need.
On the other hand, there are documents that we will want folks to find when they're searching topically. For example, we want someone searching the Windows installation topic section to find a document on "Using Plone with IIS" that focuses on Enfold Proxy to find it. Part of the consideration here is strategic. We do not have multiple, equally good, mechanisms for installing with IIS. We really want people to find that doc in the installation section.
The same thing is true of the new doc on handling multiple docs via Enfold Desktop. We do not have any other comparable products. We really want folks who use Windows front ends in an Intranet setting to find this document when they're browing topically.
If in doubt, the question of whether a document belongs should be posed to the plone-docs community for a decision.