The Fediverse has lots of blind and partially-sighted users who rely on audio screen reader software to tell them what is going on.
Here's how to make your posts more suitable for screen readers:
-Use CamelCase on hashtags, where each new word has a capital letter, for example #DogsOfMastodon instead of #dogsofmastodon. CamelCase makes it much easier for screen readers to see the different words and read them out properly.
-Don't use long groups of emoji all next to each other, these are really irritating to hear read out loud.
-Add text descriptions to images and videos before you post them. Do this by attaching the file and clicking "edit" before you post it, then add the description.
p.s. The Mastodon bug where CamelCase hashtags were being accidentally replaced has now been fixed (https://github.com/mastodon/mastodon/pull/16460).