On Concrete5.org Add-On Pages, core block used for RELATED?

Can someone (from the core team or anyone who knows) tell me, on this site (Concrete5.org) on the bottom of the sidebar of each individual add-on page is a RELATED block. As you know, it shows related Categories for the user to see add-ons in those related categories (such as Applications, eCommerce, Digital Asset Management,
Image Galleries, Interface Elements, etc. etc.)

Was this achieved with one of the core blocks in 5.7 (I'm thinking Topics List, rather than Tags)? Or was it custom?
It seems that the results sets shown when a user selects a related category is mostly accurate, and Topics can filter a set. It's just that each different add-on page shows a different set of categories (related?). How is that done? I see now with a topics tree for categories, add-ons could be in more than one category. So was a "related" set selected manually for each?

Any info and instructions is much appreciated.

View Replies:
OKDnet replied on at Permalink Reply
I think I understand... I see the "Related" categories are a subset of all the categories listed on the page list page of add-ons (when you select "Filter Results"). So is this a "Topic List" block? So the mode "Display a list of all topics for use in a search" allows you to select the Topic Tree, which would list all the categories (not a "related" subset"). But what I think donr is selecting the other option "Display a List of Topics for the current page" , which would show only those categories that were selected (in the topic tree) for that add-on (i.e. "related").
And then, if a user selects a specific category, all add-ons that had that category checked would show as a match.

Is this correct? So this is done with the core blocks? Or what?
frz replied on at Permalink Reply
We just used a custom attribute.
frz replied on at Permalink Reply
but yes, in version 7 a topic tree might be a cool choice if there are a lot of sub categories you want to aggregate by.
OKDnet replied on at Permalink Reply
Hey Franz, thanks for responding.
I get it all now. I had already used Topics in the one manner (listing all categories, and then as a filter for the list on the current page), but doing it to show "related" (to the current page, which doesn't even have a list) had me somewhat confused.
The directions here

helped. Specifically it briefly explains

Step 4. Topics List block
- display a list of topics that apply to the current page
- display all topics in a topic tree

It then goes on to illustrate the latter, but never the former (not yet anyway). But this is the "related"!

Well hopefully if anyone else is still confused, this will help.

Edit: here's the new document home
OKDnet replied on at Permalink Reply
What's also interesting that I just fully grasped, is how both the TOPIC LIST block and the PAGE LIST block have similar (but different) functionality, in that they can both be used to filter "related".

So on blog pages for example, that have Topics attributes, each can be used on a sidebar for example, to filter. So either "Related Posts", or matching categories. The demo content uses the PAGE LIST to show "Related Posts". It shows whatever it's set to show (the titles of the post typically) when loaded, and can show RANDOM matches.
The TOPIC LIST block can be set to "display a list of topics that apply to the current page" and this will show the matching Categories.for each page when loaded.

So when set up fully (in the manner I'm doing it anyway), clicking on a PAGE LIST "related posts" will display a specific post. On the other hand, clicking on a TOPIC LIST blocks "Related categories" (or whatever you want to label it) will display another Page List Block of all the posts that match.