quick version

Tag parents let you automatically add a particular tag every time another tag is added. The relationship will also apply retroactively.

what's the problem?

Tags often fall into certain heirarchies. Certain tags always imply certain other tags, and it is annoying and time-consuming to add them all individually every time.

For example, whenever you tag a file with ak-47, you probably also want to tag it assault rifle, and maybe even firearm as well.

Another time, you might tag a file character:eddard stark, and then also have to type in house stark and then series:game of thrones. (you might also think series:game of thrones should actually be series:a song of ice and fire, but that is an issue for siblings)

Drawing more relationships would make a significantly more complicated venn diagram, so let's draw a family tree instead:

tag parents

Let's define the child-parent relationship 'C->P' as saying that tag P is the semantic superset/superclass of tag C. All files that have C should also have P, without exception. When the user tries to add tag C to a file, tag P is added automatically.

Let's expand our weapon example:

In that graph, adding ar-15 to a file would also add semi-automatic rifle, rifle, and firearm. Searching for handgun would return everything with m1911 and smith and wesson model 10.

This can obviously get as complicated and autistic as you like, but be careful of being too confident--this is just a fun example, but is an AK-47 truly always an assault rifle? Some people would say no, and beyond its own intellectual neatness, what is the purpose of attempting to create such a complicated and 'perfect' tree? Of course you can create any sort of parent tags on your local tags or your own tag repositories, but this sort of thing can easily lead to arguments between reasonable people. I only mean to say, as someone who does a lot of tag work, to try not to create anything 'perfect', as it usually ends up wasting time. Act from need, not toward purpose.

how you do it

Go to services->manage tag parents:

Which looks and works just like the manage tag siblings dialog.

Note that when you hit ok, the client will look up all the files with all your added tag Cs and retroactively apply/pend the respective tag Ps if needed. This could mean thousands of tags!

Once you have some relationships added, the parents and grandparents will show indented anywhere you 'write' tags, such as the manage tags dialog:

Hitting enter on cersei will try to add house lannister and series:game of thrones as well.

remote parents

Whenever you add or remove a tag parent pair to a tag repository, you will have to supply a reason (like when you petition a tag). A janitor will review this petition, and will approve or deny it. If it is approved, all users who synchronise with that tag repository will gain that parent pair. If it is denied, only you will see it.

parent 'favourites'

As you use the client, you will likely make several processing workflows to archive/delete your different sorts of imports. You don't always want to go through things randomly--you might want to do some big videos for a bit, or focus on a particular character. A common search page is something like [system:inbox, creator:blah, limit:256], which will show a sample of a creator in your inbox, so you can process just that creator. This is easy to set up and save in your favourite searches and quick to run, so you can load it up, do some archive/delete, and then dismiss it without too much hassle.

But what happens if you want to search for multiple creators? You might be tempted to make a large OR search predicate, like creator:aaa OR creator:bbb OR creator:ccc OR creator:ddd, of all your favourite creators so you can process them together as a 'premium' group. But if you want to add or remove a creator from that long OR, it can be cumbersome. And OR searches can just run slow sometimes. One answer is to use the new tag parents tools to apply a 'favourite' parent on all the artists and then search for that favourite.

Let's assume you want to search bunch of 'creator' tags on the PTR. What you will do is:

If you want to add or remove any creators to the 'aesthetic art' group, you can simply go back to tags->manage tag parents, and it will apply everywhere. You can create more umbrella/group tags if you like (and not just creators--think about clothing, or certain characters), and also use them in regular searches when you just want to browse some cool files.