Selective Attributes

I'm setting up a new 2.1.0 shop to upgrade from my old 1.58 shop. In the new shop I want to offer a choice of styles (t-shirt, hoody, totebag, polo, etc), colors (Black, Grey, Red, White, etc), and sizes (S-6XL). I have all the attributes and values in the new shop. The problem is that certain sizes are only available in certain styles. Ditto for colors.

For Example a black t Shirt is available in S-6XL.
a red Hoody only in S-XXXL
and a tote bag doesn't have sizes.

I know that I can assign certain colors, but how do I restrict different combinations?
If there's another thread please direct me to it. My searches didn't bring up much that looked useful.

That's what the Products' Options' Stock zc_plugin is used for. Documentation: https://github.com/lat9/options_stock_support/wiki

Note that some of that documentation might not be up-to-date, since the feature was introduced into the Zen Cart core.

If it's part of the core 2.10 installation, how do I configure it in Admin. There's nothing for it in either Configuration, Catalog, MOdules, or Tools.
So far nothing in the Wiki seems to apply to my brand new 2.10 install.

Under Catalog, you'll find Manage Options' Stock.

That's where you add, change, or delete.

Here's what my config menu looks like.

It would have been nice if someone had let me know you needed to go to plug in manager and install POSM.

To track variant stock in Zen Cart 2.1.0 and higher using POSM:

go to Admin > Modules > Plugin Manager
install Products’ Options’ Stock Manager
Users of the Responsive Classic template will need to change the configuration value Dependent Attributes: Outer Selector.

Since the initial use of Plug-ins, it can be confusing since the forum site lists all Mods and Plugins under Plugins.

The first line of the Wiki does say that it is a plugin.

BTW, if your configuration menu stops at EZ-Pages, you may need to check if any other included plugins need to be initialized.