[Guide] How to filter unwanted content? Creating custom filters

Filtering out unwanted content is an important feature of Furbooru, this post is intended to explain the most important aspects of it.
 
Site Rule #4 states that:  

 
If you don’t like some type of content please use your filters to hide it instead of downvoting.
 
To be able to filter things you first need to create a custom filter. To do this go to https://furbooru.org/filters/new and fill appropriate fields. You can also edit any of the preexisting filters by clicking on “Copy and customize” when you go to Filters page.
 
You can either just spoiler images containing certain tags or hide them entirely. Spoilered images will display a placehold image instead of the actual image. The behavior of the placeholder image can be changed from the dropdown menu in the upper-right corner:
 
 
For example if set on “hover” then placeholder image will disappear when mouse cursor is placed on top of it:
 

 
Besides spoilering/hiding only individual tags you can also create complex expressions. Those will filter out all results of queries that you add here:  

 
For example the line

will cause all images tagged cat that are safe to be hidden (so images tagged cat that are not rated safe but instead suggestive, questionable, explicit, grimdark etc. will stay, unless those tags are hidden on their own). The line

will hide all images with raccoons except those where there are also dogs, and the line

will cause all images tagged werewolf that are NOT explicit to be hidden (so only images tagged werewolf that are also tagged explicit will remain).
 
By using complex filter you can even hide all or some images uploaded by individual users. To do that go to their profile and click on “Uploads”:  

 
The part that needs to be copied into complex filter can be then found in the search bar, in my case it is:
 

 
For example to hide all images uploaded by me that are tagged with “fox” you need to add this text to your complex filter:

 
if you want to hide everything uploaded by me add:  

 
More comprehensive list of available options can be found in Search Syntax Help.
 
 
You can hide images based on their score, fave count, file extension, size, creation date, source url and many more.
 

 
When you are done, save it and then on the next page select “Use this filter”:
 

 
Once a custom filter is created and in use you can then either spoiler or hide individual tags by just hoovering over tags under an image and selecting appropriate option from the dropdown menu, the tag will be then added to your current filter:  

 
Hope this helps!

I feel like that was really needed to be posted, thank you!  
It’s such a shame to see normal posts get downvoted, especially when there’s not that many upvotes to begin in the early phase of the website. Have there been any serial offenders caught using downvotes as “I don’t like” button yet, if you don’t mind telling us?

@Anonymous #7878  
Yes there were, I PMed a few users about using filters instead of downvoting. One of the reasons I created this thread was that in the future I can show it to people who engage in indiscriminate downvoting instead of explaining how to use filters every time via PMs.

Dang, even after using Derpi filters thoroughly for years, I never knew that new lines in complex filters create new expressions. I’ve been formatting everything as (expression 1) OR (expression 2) OR (expression 3) until now.

I am hoping I can do more to filter tags. I have to ask; “when it comes to the anonymous user uploads is it possible to filter out specific things for those?”
 
Side note  
Still learning this taging system. I am very aware that my lack of understanding of the system may seem aggrivating. Not entirly sure I am breaking a rule by learning. I have a feeling that some of my questions seem flamitory to some. I do apologise if that is the case. I make mistakes because I am human.

@LP2Lily  

It is possible to hide all uploads done by anonymous users. Just add this line to your complex hide filter:  

 
Yuo can of course combine this with other tags to make more specific filter that would hide anon uploads only for specific themes.

@CruFox
 
Thanks for the helpful solution and kindness! Your awesome!

Honestly, when I’m making a custom filters, I was afraid if my filters become publicly. And I’m glad they don’t.