The issue is whether you have an opening rectopg. If so, you need an opening versopg as well.
In the following case, when next is specified, it will always call the opening rectopg page model, inserting a blank page if necessary because no opening versopg page model is available. body.recto0 will be used first, then body.verso1, then body.recto1.
<rectopg>...<pagespec pgid="body.recto0"...</">
<rectopg>...<pagespec pgid="body.recto1"...</">
<versopg>...<pagespec pgid="body.verso1"...</">
However, when an opening versopg model is also available, the formatter will call either the opening rectopg or the opening versopg depending on which is appropriate, and a blank page will not be inserted. body.recto0 could be used first, then body.verso1, then body.recto1. Or body.verso0 could be used first, then body.recto1, then body.verso1.
<rectopg>...<pagespec pgid="body.recto0"...</">
<versopg>...<pagespec pgid="body.verso0"...</">
<rectopg>...<pagespec pgid="body.recto1"...</">
<versopg>...<pagespec pgid="body.verso1"...</">
Note that in the first case, you could define an opening versopg, but if the page call always specifies recto, the versopg page model will never be used, so it isn't included. In the second case, either opening page model can be used as the next page.
Suzanne
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