There are two steps: make the anchor and then link to the anchor.

Step 1: In the page you are linking TO, give the anchor a name by putting your cursor in front of the content and click on the flag.
Give it a unique name [example: anchor_link]

documentation on anchors image

 

Step 2: In the page you are linking FROM, the text you want linked, hightlight your copy [example: a list in the secondary content area]. Then click on the globe. Use the node, node number, plus #name_of_anchor.

The link will follow this pattern:
/node/000000/#anchor_link

anchor link

 

It is important that when you execute an anchor/link to another page other than the one you're on, you have to select the "URL" link type and use the node#, not the "Link to the anchor in the text" link type. It will look like this: