Valve "didn't like" Steam pages linking to other pages, and it's "enforcing new rules" on what devs can write on its store

gamesradar.com:

Beginning in early September, Valve is making some changes to "what can and cannot be included" in Steam store page descriptions, ruling out links to other websites, embeds that mimic Steam store UI, and links or embeds to other games on Steam. 

A fresh Steamworks Development post outlines the new rules, targeting four areas of Store pages: About The Game, Short Description, Special Announcements, and Awards. "We'll be enforcing new rules for what can and cannot be included in your written store page descriptions," it begins. Valve says this is partly a follow-up to a previous change about demo visibility on the storefront, which gave demos their own separate pages and let them behave like free games in store lists. 

Valve doesn't mince words in its explanation of the changes. "We didn't like the trend of store pages linking prominently off to other store pages," the post reads. "We have been seeing more and more store pages that are effectively advertisements for OTHER [caps Valve's] store pages on Steam. This meant that on some game pages in the Steam store, you would find lists of two, three, or even eight other games before you even got to read the description of the game you were looking at. We don't think that's great for customers trying to learn about a game on Steam and so we wanted to update the rules to prohibit games from using the written description area for linking to other games on Steam."

The only exception here, Valve says, is for separate prologue-style sections that some developers have taken to releasing on Steam as free samples in lieu of demos for upcoming games. Valve says it was "fine" to release prologues like this, "except that they were confusing for players," and reckons that with the changes to demos it should now be "unnecessary for developers to purchase a separate appID to use for prologues," as they can instead "use the demo appID that is already associated with their game." 

Valve isn't banning prologues outright, but says demos