r5 prefix Solid Enchant Missing from chart?!?!

I don't know what you're asking.

The wiki lists "Stable" as being -9%.

And you also said "9, not 6", rather than "6, not 9".

If you're referring to "Furthermore, the enchant that's supposedly the same, "Stable", has a repair cost reduction of 9%, not 6%.", I was saying "Furthermore, according to the wiki, the enchant that's supposedly the same, "Stable", has a repair cost reduction of 9%, not 6%."

Well, two different ways to interpret that statement.

Also, the description says 9, so that's probably why it's been like that for so long, despite the effects of the ES being 6.

So we're sure there's not an enchant very similar to Solid that actually is -9%?

Yes. It has 2 different names, oddly; one that appears on equipment and one that appears on the enchant scroll. Unfortunately, many enchants suffer from this.

Alright, I understand now the "light armor" confusion...

"Light" Melka Chain Mail is actually heavy armor, despite its name.