To manage languages of catalog contents, you must edit the language of the catalog itself - all children content (categories, products, skus) will inherit the language of the parent catalog.

/Q

Is there any way to change this? We have a huge international catalog. Maintaining 15 different catalogs is going to be impossible. What's the point of having culture specific properties, but not allow culterspecific availability?

Basically no - it's the way languages work for catalog content - the catalog defines all the languages. You can still define all 15 languages on your catalog, but for each catalog content, set the status for each language separately - if you don't want a product to be available in a language, then make that version unavailable.

This can be handled better with Market concept.

Where do you associate a product with a market? I don't see this in Catalog UI or Commerce Manager.

I don't see the Markets tab on the product or category level. The only place I see this is on the catalog level, which again, if I went that route than I'd have to have 15 different catalogs as all of our products have products that vary by region.

I'm on Episerver Commerce 9.11, if that means anything.

Market is per-entry level - you can surely see it on product level. But not category.

If you want to make an entire category available or not in a market, you'll have to do some works to make its entries available/unavailable in that market. Will require some coding, and of course that feature is not available in the UI.

ok, so you can't make a category not available in a market but you can on the entry level. I'm looking at Catalog ui for an entry. Below is a screenshot, where do I need to go from here to edit the markets this entry is available in? 

If you look at my screen shot above, the click on Change close to Markets All (top center of your image) 

How could I miss that?! That is exactly what I'm looking for. Thanks!

Just a heads up in case this issue comes up in the future, even though you said this feature isn't supported for categories, I was able to successfully add the markets functionality to my category class. I needed to add the code below as a custom property. It wasn't there before, but it is by default inherited from the product class. After adding this property the markets is now working beautifully on everything. Again thanks for you help in pointing me down this direction.

Here is the code.

        [Display(GroupName = "EPiServerCMS_SettingsPanel", Order = 400)]
        [IgnoreMetaDataPlusSynchronization]
        [UIHint("marketsselector")]
        public virtual ItemCollection<string> MarketFilter { get; set; }

Here is a screenshot of it working on a category.