This raises more questions than it answers. What does installation mean in this context? What's an installable module? Does it mean that I cannot use a module with no / empty default profile at all? Can a module be installed if it defines a default profile but the package manager decides not to install it, despite the recommendation?

@psabata is modulemd a place to answer those questions?

@ttomecek The specification includes the following description of profiles:

    # Profiles define the end user's use cases for the module. They consist of
    # package lists of components to be installed by default if the module is
    # enabled. The keys are the profile names and contain package lists by
    # component type. There are several profiles defined below. Suggested
    # behavior for package managers is to just enable repository for selected
    # module. Then users are able to install packages on their own. If they
    # select a specific profile, the package manager should install all
    # packages of that profile.

From my point of view this covers the recommended behavior for package managers quite well. We could make it more specific, mandating specific user interface terminology and implementations but is it necessary?

I don't know what installable means in your comment. Certainly a module with no or empty profiles won't install any components but it still needs to be possible to enable it and install RPMs from it manually.

I kind of missed that section. I think it summarizes the use case quite nicely, thank you!

@dmach ^

Closing then.