Bookmark hygiene, one entry only

Your Tor Browser bookmarks should have one bookmark for Nexus. Not five. Not one per mirror.

Bookmark the mirror reference page on this Bureau site (or wherever else you trust to keep the current signed rotation fresh). One entry. When you open the bookmark, you land on a page that lists the current mirrors, and you copy from there.

Do not bookmark individual onion addresses. Onion addresses rotate. A bookmark that points at an address the operator retired six months ago is a phishing risk if anyone happened to snap up the retired address (they usually do).

Reference-page bookmarks stay valid across rotations. Address bookmarks go stale. This is the difference between a bookmark that reads for years and one that fails as soon as the operator does their job.

The failure this prevents

A bookmark pointing at one raw address eventually goes stale, because addresses are retired and replaced. The moment it stops working is the moment somebody goes searching, and searching for a marketplace address is the single most reliable way to arrive at a cloned one. Saving the whole published set rather than a favourite removes that moment. Comparing your saved copies against the published list occasionally, while everything works, keeps it removed.

Where not to keep them

Anywhere that syncs to a service under your name. A note application backing up to a cloud account attaches those addresses to your identity, which is an odd thing to arrange deliberately. A bookmark folder in the browser, a password manager entry on your own machine, or paper all avoid it.