Anchor ID:

An alphanumeric ID that is used as the address of the anchor. Use a descriptive ID that is easy to identify. These IDs are displayed in the tab and in the Insert Hyperlink dialog.

You cannot use spaces or special characters. A warning will be displayed if you try to use illegal characters.

Help Context:

You can assign help context numbers to anchors so that you can make context-sensitive calls to specific positions inside topics. If you have activated the automatic generation of context numbers for anchors a number will be displayed here automatically.

Keywords:

You can also assign index keywords to anchors (normal K-keywords only, A-keywords are not supported here). If you do this selecting the keyword in the index will jump to the anchor instead of the top of the topic.