Normally you only have one item in the Table of contents (TOC) for each topic file. However, there may be some situations where you want to use exactly the same topic in more than one place in the TOC.
You can do this by creating multiple references to an single topic in the TOC. The result is a single TOC topic that can be accessed from multiple positions in the TOC. There is still only one topic, but it is displayed in several different positions within the TOC – for example in different chapters.
Sometimes it is better to create a copy or to use an embedded topic. See Snippets and multiple TOC references for more background information.
Multiple TOC references are not copies of topics. There is still just one topic file but with two items pointing to it in the TOC. It is like a single room with two doors.