Someone who saves or shares a page expects its address to keep working. Its usefulness depends on remaining recognizable and leading to the intended content as the underlying system changes. A filename extension in an address need not cause a problem, but changing how files are stored should not unexpectedly send readers elsewhere. Choose public routes deliberately, give the content a stable identity, and preserve useful incoming paths when a migration or editorial change makes an address move.
Preserve the reader’s destination as the system changes.
A reader saves an article and returns months later. Changing the tool used to publish it should not make the saved address fail. A stable public route separates the reader's destination from the files and systems that happen to deliver it. An article stored under one file structure might later be delivered from a database without changing the address the reader bookmarked. If the public address does need to move, the old one should lead somewhere intentional. People can then keep using their existing links while the site changes how it stores the content.
Choose words that describe the content and preserve useful old addresses when the structure changes. The goal is continuity for the person sharing, saving, or following a link. A clear address helps people recognize the page they are saving or sharing. Keep a useful existing address working even if you choose a neater one. Preserve access to the content, especially when other pages already refer to it through that address.
Put it into practice.
Choose a primary public address for each lasting piece of content, independent of where its files or records are stored. Before changing a public route, identify where its existing address is used and decide how old links should behave. Verify both the new destination and the retained paths. Update internal links and search metadata consistently. Keep a title refinement separate from an address change unless there is a real reason the address must change too.
Will a link shared today still lead somewhere useful later?