Armour/Hybrid pen marks meant either Armour marks or Hybrid pen marks. I see how it could be misunderstood, sorry.

The thing about hybrid pen marks is that they are very efficient compared to magic pen marks: you don't lose that much magic pen for some armour pen. And since your E is a gap closer and then you should be able to slow your opponents with your Q, you should be able to stick to your opponent and auto him during that time. That said, I think it purely is a matter of preferences.

Ok, I see where you're coming from with a lot of suggestions and I do agree that my rune page isn't optimal, however I do disagree with your suggestion of Armour/Hybrid pen marks, as Zac simply doesn't autoattack often enough to benefit from them.
Thanks for the useful critcism, and I will update the guide shortly.

I see many problems in your guide so I'll try to make a list of them:

Runes:
Your setup is very poor, makes you very squishy in the early to midgame and thus, makes you very abusable in lane because you have neither resistances nor health: health per level runes need a bit of time to scale up plus you took them in marks and glyphs which are really poor in general. You ABSOLUTELY need armour.
Plus gold generation isn't going to help you at all to fight which makes you a very very weak Zac support in lane without any presence.

The setup I'd run: armour/hybrid pen marks, flat health seals, flat magic resist glyphs and armour quints.

Runes only have a big impact when it comes to the early game and thus are really important when it comes to the bottom lane because of how impactful early trades are. By taking a good trade at level 1 for instance, you can completly zone out you enemy. I can't stress how important a good rune setup for supports is.

This is the biggest flaw I saw in your guide: your rune setup is really far from being optimal.



Items:
If you take Wealth you can start with 4 potions instead of 3 :)

Spirit Visage should not be a core item because, as a support, it's a very selfish item, and you'll rarely have enough gold to purchase it before the later stages of the game: I don't think that you should ever be able to finish this item during the laning phase. If you need health and regen, you'd rather rush face of the mountain as it is cheap and cost efficient.
What's more, it's far from being core if you face a full AD team.
Since you seems to really like the item, I'd put it in situational but, as I said, it's a really selfish item that a support should not really be buying: if you need magic resist, you'd rather go for a Locket of the Iron Solari.

What I'd list as core items: Sightstone, Mobility Boots and Sweeping Lens.
FotM could be core but in certain situations, you want to get Locket asap.
So pretty much every item is situational: need magic resist? Get Locket. Need to help your carry to survive? Get FotM/Miakel's. Need armour? Get Randuin's.

Mobility Boots are really good to ward the map without getting caught.

Even though you don't use mana, you should mention Mikael's Blessing. This item is super good/essential against certain team comps.




I think that Zac support can work but I think that your runes and build aren't the optimal ones.
Feel free to discuss whatever I've said and good luck with your guide :)