# Why are unplaced part titles creating empty pages in ConTeXt?

I made a book which is divided into parts, with `\part{}`. I want these parts to appear in the table of contents, but do not need them to appear within the document itself. I added `\placehead=no` to the `\setuphead` settings, which makes the title not appear, however, when `\setuppagenumbering` is set to `alternative=doublesided`, two completely empty pages are created.

``````\setuphead[part][number=no, placehead=no]
\setuplist[part][alternative=c]
\setuplist[title][alternative=c]
\setuppagenumbering [alternative=doublesided]
\starttext
\definecombinedlist[content][part,chapter]
\placecontent
\part{Animals}
\chapter{Birds}
\chapter{Snails}
\part{Plants}
\chapter{Flowers}
\chapter{Mushrooms}
\stoptext
``````

The `\part` commands seem to be creating empty pages at page 2, 3, 8, and 9. Without the `\part` titles, these pages disappear.

How can I have parts in my document which are invisible, but not in the table of contents, and which also do not create blank pages in the document?

-

The page break is controlled independently by the page switch. The structure levels `\part` and `\chapter` default to the value right, which means in double-sided context that the respective headings are always located recto at the top, hence the extra blank page if the command is encountered on odd pages. (The `page` key inherits functionality from the `\page` macro.) To suppress the break you need to set it to no:
``````\setuphead[part][number=no, placehead=no, page=no]