Can my paper be published in a conference's special issue against my will? I am thinking on sending a paper to a conference. However, the conference CfP says:


  The Journal XX will publish a special issue with a selection of papers presented at the conference. The selection of the papers will be made by the Scientific Committee of the Conference.


Now, if I get accepted into the conference, and my paper is selected to be published in the journal, can I oppose it, or am I forced to accept it by the sole fact of participating in the conference? In other words, if I do not want my paper published in Journal XX, is it fine for me to apply to the conference?
In my experience, there are typically two classes of conference special issue, and the answer to your question will depend on which one this conference is using.


Some conferences simply have their entire proceedings published as-is, "converting" them into indexed journal articles for the benefit of people in departments or fields where conference articles do not count.
"Selected papers," on the other hand, typically refers to inviting the best papers of a conference to be upgraded into better articles for final publication, presumably on the basis of continued work and feedback received at the conference, and typically with an expedited peer review process.


The statement that you quote is unclear, since it says only selected papers, but doesn't mention invitations, extended versions, expedited review, or any of the other words typically involved with the second model.  Moreover, if the conference is not very good, it may be that they simply don't care.

I would thus recommend writing to the organizers for clarifications --- and make sure it's a conference that you really want to be at.