SeraphimWarmachine said:

Each identity has a limit to the amount of out of faction influence can be in their deck. In the core set, all the identities have an influence limit of 15.

Each faction card has a meter with 0 to 5 influence. You can have any number of out of factions cards with influence that totals to less than or equal to your limit. If the card has no influence bar, you can't include it if it's not in your faction.

All the faction agendas in the base set have no influence bar and thus cannot be included in the decks of other factions. All the neutral cards in the base set have an influence of 0 so you can have as many of those as you want in your deck.

For example, NBN's identity has an influence limit of 15. NBN decides to bring in three copies of Weyland's Scorched Earth (influence 4) and three copies of Weyland's Aggressive Negotiation (influence 1).

(4x3) + (1x3) = 15

NBN has now added as many out of faction cards as they are allowed.

SeraphimWarmachine said:

While this has been answered now already, I wanted to point out that the rulebook is available as a pdf download in the Support section of the website.

 Just to answer an earlier question, there are 3 of botj Matrix Analyzer and Data Raven available in the core set. 

During the Icebreaker, there was a lot of scorched earth running around, but not so much data raven. Looking back, I agree, running taggers from NBN In a wayland deck is far more efficient, especially because you could then also include Snare from Jinteki that is net damage plus an automatic tag.

It's in the manual ( you can find it in the "support" section of the Android: Netrunner product subsite) on page 24. It's simple, your identity determines how much Out of Faction influence your deck can contain (currently 15 for all identities). Cards with no faction don't count, and cards with no influence rating aren't available out of faction (think of this as infinite influence).

I think the best way to run Scorched Earth in NBN is to run 2x Scorched Earth, 1-2x Archived memories. Each Archived Memories has two influence cost, so the total influence cost is still below the 15 mark if you run 2 of them. Also, Archived Memories are MUCH more useful in some match ups, and Scorched Earth is frequently a dead card early game, whereas Archived Memories gives you some additional toolboxing to pull back traps, discarded ICE, and credit generators (if you're really hard-pressed for a Pad Campaign, for example).