All out, i.e., without a hyphen (not to be confused with all-out, i.e., with a hyphen) is used in reference to groups of people. A group of people is said to be all out if everyone in that group has publicly stated that he or she is lesbian, gay, transexual, bisexual or queer. If anyone in the group is not LGTBQ or if anyone in the group is LGTBQ, but has not yet made a public declaration of that, the group cannot be said to be all out.
This makes it very difficult for any group to be all out. While most of the stigma that used to be attached to LGTBQ is now largely—although, unfortunately, probably nowhere entirely—gone in many communities, it’s unlikely that any group, even one that focuses on advancing LGTBQ issues, excludes all straights. Even if there is one straight person in the group, that group can’t be said to be all out.
And then there are those backward areas where there is still a strong stigma attached to being LGTBQ. Counter-intuitively, those areas are more likely to include all out groups than more accepting communities. It’s true that in areas where bigotry reigns supreme, above-ground LGTBQ groups are, for safety reasons, less likely to form. However, in those areas, straight people will, again for safety reasons, almost never join the few LGTBQ groups that do form. Thus, the groups that do form are more likely to be all out.