I had originally posted this on my main, but I wanted to shuffle it here & refresh it a lil bit 
I want to start by saying: This is a bit of a long post, but it's not an exhaustive guide by any means, and there are always case exceptions! This is just how I use these tools, and I hope that it's able to help some other folks. Especially because some of these tools, we may not have had anything like them on other sites! And, if you're ever not sure about something, make note of that in your post, and folks should be able to help clear things up for ya!
Also, before we begin, I highly recommend reading Cohost's Community Guidelines if you haven't already!
Tagging, Tag Muffling, Tag Filtering, Tag Silencing
You're almost certainly familiar with tagging already! They function about like you expect tags would: You put a tag on your post, and then folks who are searching for that tag can find your post. Very important here, because Cohost, by design, doesn't have any sort of algorithm for discovery otherwise, and Search only looks at tags, not post content!
These are also super helpful for folks who wish to filter out certain content that they don't want to see. For example, I generally do not have interest in livestreams, so I have several tags related to livestreaming muffled. As in the image above, when I find a post that has those tags, Cohost hides the post, tells me which muffled tags are on the post, and gives me the option to view the post anyway, if I want. You can muffle tags by going to Settings -> Filtered Tags -> Muffled Tags.
You can also silence tags, which prevents them from showing up on your timeline altogether. You can silence tags by going to Settings -> Filtered Tags -> Silenced Tags. The list of tags you already have silenced is hidden by default, so you don't have to see them if you don't want to when you're just checking your settings page.
For both discoverability and content filtering reasons, it's strongly recommended to robustly tag your posts! What we mean by this is, try to make sure your posts have several relevant tags on them, relating to the content of the post, maybe even the tone (e.g. "vent") or anything else you feel might be relevant. Tags persist through shares - if someone shares your post, your tags remain visible. This is extremely helpful when posts are hidden by Content Warnings or 18+ Content Warnings, as the tags add useful context for what's hidden behind the warnings. Also, beyond that, many folks like to add asides or context to tags - much in the way people do on Tumblr.
Leaving a post untagged essentially leaves it as "followers only" - it won't show up in search - but please keep in mind folks who use tag muffling when you do this, just in case. These posts are also very hard to find later, if you need to reference something.
Content Warnings, CWs
Content Warnings on Cohost function by hiding the post with the warning, letting users know which warnings have been applied to the post, and letting the user decide whether they want to see it or not. Similar to tag muffling, but rather than relying on the user to enter in what they don't want to see, Content Warnings hide the post from all users who do not have the specific warning(s) on their Allowed list.
You can add a Content Warning to your post by clicking on the "warning" icon at the bottom of the post editor (looks like a triangle with an exclamation mark in it), then typing in any content warnings you wish to apply. They function like tags (separate them by commas). Use the preview post function to see what your post looks like with the CWs to make sure they've applied properly before you post!
The intent of this is to hide potentially sensitive topics from those who do not wish to see them without a heads up first. This can range from things like general weird stuff, to game or show spoilers, to heavy world events and politics, to extremely distressing / sensitive content ("triggers").
These are also used to hide flashing or blinking images that may be hazardous for photosensitive users. If you aren't sure if your image might be hazardous, it's better to err on the side of caution and hide it anyway, just in case.
If you're adding a Content Warning for sensitive content, please do not use euphemisms or memey language when describing the subject - be direct with what the content warning is about. Not everyone will understand what a specific euphemism means, and it also makes it more difficult to filter.
Cohost gives you three Content Warning settings: Never show certain CWs, Always show certain CWs without click-through, and Show ALL content warnings without click-through (use at your own risk! that setting does respect your "Never Show" rules though!). You can find both settings under Settings -> Filtered Content Warnings.
I recommend that, if you have a Never Show filtered content warning, also put that in your Filtered Tags list, to help catch any posts that may have that content tagged, but no Content Warning.
Special Note: When to use a Content Warning
It's strongly recommended to tag things with sensitive subjects, whether or not you apply a content warning, to help folks filter out things they may not want to see. It's also recommended to reserve Content Warnings for things that are strongly sensitive, upsetting, or otherwise distressing.
There is a very good post thread here that discusses, specifically, content-warning "food" - folks recommend tagging food posts with "food" so that folks who struggle with ED can filter those posts out, but not using a content warning for it, as that can set a harmful tone of "food is dangerous". This thinking can be applied to quite a few other topics, but food is a very common one.
Some good metrics to gauge whether you would apply a content warning that I have seen are:
- Would you use a spoiler tag on it, if you were sending it in, say, Discord?
- If it were on TV, would it have a Viewer Discretion advisory on it?
Use your best judgement, and ask if you are unsure! And if you come across a post that you strongly feel should have a Content Warning, politely comment and ask the OP to consider adding one!
Adult Content, 18+ Content, NSFW Content
18+ Content tagging lets you mark your content as For 18+ Viewers Only. This will hide the image much like a CW would, but with a more general "this content is adult" warning instead. It's recommended to look at the post's tags, which are visible regardless of the 18+ warning, and any applied Content Warnings to get a gist of the content.
18+ Content tagging on Cohost is really simple: there's a checkbox in the upper-right corner when you're making a post that asks you whether it's 18+ content or not. Check that box, and you're all done!
If most or all of your page's content is going to be 18+ Content, you can save yourself a few clicks by setting your entire page to 18+ Content by going to your profile, hitting the Gear settings icon in the sidebar, then checking the 18+ Content box. This will apply the 18+ content tag to all of your posts by default. (Your profile picture & banner must still be all-ages appropriate though, do note!)
Marking a post as 18+ Content hides it from folks who have "hide 18+ content behind a clickthrough" in Settings, as well as hiding it entirely from users who are under the age of 18.
Extra note: You don't need to CW something as "18+ Content" or "NSFW" or the equivalents as long as you use the 18+ Content tag. You could use the CW field to describe what exactly makes the post 18+ Content, though, or if it's a flavor of 18+ Content that you feel folks would like a heads up before they see! If you apply a CW to an 18+ content post, it'll show up like so, combining the click-throughs for both CW and 18+:
Special Note: Post Silencing
This tool is mostly useful for if you see a post that you don't like, or end up seeing the same post a bunch of times and you're tired of it. Use the "meatball menu" in the top right of the post and select Silence Post. This will stop that post and any shares from that post from showing up in your timeline again, until you un-silence it in Settings.
You can also silence users, if you need to, by going to their page, using the meatball menu on their sidebar, and selecting Silence (username). This is a way to avoid seeing posts from a certain user, without actually blocking them - maybe you're just tired of their content but you don't really want to outright block them. You can un-silence a user through this same menu (on their page), or through your Page Settings (via your profile) -> Silenced and Blocked Pages.
Silencing is not a replacement for the use of robust tagging and Content Warnings! It's very helpful for once you've already seen a post, but the above mentioned tools are for avoiding seeing the post in the first place.
That's all for now!
If I forgot something or you have something to add, please let me know in the comments! I hope this helps!
Changelog:
**Edit 1:** Added more detail to Content Warning section, re: less-serious content advisories**Edit 2:** Added section about "When to use a CW"
**Edit 3:** General revision; specific edits to reflect that shared tags now show on posts; updated wording from "Adult Content" to "18+ Content" where applicable to reflect site term change, added photosensitivity to the CW section
**Edit 4:** Updated to reference Tag Silencing
**Edit 5**: Changed Discord image links to Imgur links; rewrite some sections to incorporate the previous updates instead of tacking them on at the bottom, general revisions
