Due to the prevalence of spam and phishing throughout the Steam community, links (URLs) are sometimes hidden with the text:
Steam will hide links for a variety of reasons outlined in this article. If your link is being filtered, make sure to check all the scenarios below.
When community items are suspected of containing malicious content, all links attached to that content will temporarily be hidden. This content includes user reviews, screenshots, discussion posts, comment threads, etc.
Steam automatically reviews all suspicious content to confirm whether or not it's malicious. Once we can make sure that it is not, the link will appear normally. This process should not take more than 24 hours.
Limited Steam accounts have additional restrictions when sharing links throughout the Steam community. If a link you posted in the community or on your profile is being hidden, you'll want to make sure that your account is not being limited.
Our Limited Account article explains this account status in more detail.
Link shorteners and other tools to obscure links will typically result in the link being hidden. Avoid using link shorteners in the Steam community.
If you are posting a URL with a free or less common top level domain, it is possible that domain itself is being filtered. For these domains, you want to avoid having any parameters after the TLD within your link.
For example if you want to link to your site at yourwebsite.top, make sure that nothing comes after the .top in the URL. For example, yourwebsite.top/anything would be filtered.
If none of the above cases are responsible for your link being filtered, it is possible that the link itself has been blocked by Steam Support. These links include pornographic sites, referral promotions, some advertising, free web-hosting and others. If you think your link is being filtered mistakenly, please reach out to Steam Support.