Given scene/plot descriptions from movies or TV shows, and given a specific question about the scene, summarize the question into a title

Example input: At the beginning of the movie Gangs of New York, Priest Vallon tells his son not to wipe the blood of the blade after he's cut himself shaving, saying "The blood stays on the blade". I've watched the movie multiple times, but can never find what the meaning behind that phrase is. Anyone able to shed some light on this?
Example output: What's the meaning behind the phrase "The blood stays on the blade"?
Example explanation: A person gives a detailed description about a scene from the movie Gangs of New York and asks the meaning of a said phase in the scene. The question is summarized as What's the meaning behind the phrase "The blood stays on the blade"? for easy indexing the next time someone searches for a similar phrase
Q: While looking for various actors and actresses I keep coming across material they have done that isn't on their IMDB profile. An example is Allison Scagliotti is in a web short yet there is no mention of it on her page, the web short did give her credit but this isn't always the case. I've noticed that music videos and web videos don't normally show up on IMDB as well as sometimes older roles that the actor/actress doesn't acknowledge. Since IMDB is generally the go to for if an actor/actresses was in something. If it's not listed on IMDB or their wiki page (and in some cases I've come across not the actor/actresses own personal page) then how can I make sure if the actor/actress is the one I believe they are?
A:
How to correctly identify an actor/actresses is in something that is not listed on their IMDB profile?