1.5. Overview of Crypt Cards
Each of a vampire's Discipline symbols is in the shape of either a square or a diamond. A square-shaped Discipline symbol means that the vampire has one level of that Discipline, the basic level; he can use only the basic (plain text) effect listed on a card that requires that Discipline. A Discipline symbol within a diamond signifies that the vampire has an additional level of that Discpline, the superior level, and therefore may opt to use either the basic (plain text) or the superior (bold) effect listed on the card (but not both).
This would indicate that Striga and Maleficia are in fact disciplines. Treat them as disciplines when you play them. However, all Maleficia and Striga cards have card text stating they are not disciplines. That text does not change the requirements to play the card.
1.6.3. Minion Cards
In many cases, a minion card will have a Discipline symbol, a clan symbol and/or a blood cost; in these cases, the card can only be played by a vampire who meets the requirements.
There are other requirements for cards that are not stated by the rules, such as sect, titles etc. Why can't Chandler Hungerford play the Second Tradition? I can ignore "Requires a Prince or Justicar" because the rulebook doesn't tell me how to play a card that says that.
The card text "

is not a discipline" does not remove the requirement that the vampire must have

in order to play the card. The text is there to prevent Ian Forestal from having

and to prevent "Agent of Power" or "Spontaneous Power" from granting

. It prevents Pherydima from stealing

with "Absorb the Mind."