Mag plugs and chip detectors
Some engines will have 1 or more electrically connected chip detectors that when triggered will turn on a light in the cockpit warning of a potential problem, others have a magnetic plug that is not connected to anything.
These mag plugs need to be removed and inspected at specified intervals, normally at the Daily Inspection, but occasionally at scheduled checks dependant on engine make/model.
An indication of a chip is generally part of fair wear and tear, and the detectors are deliberately made as sensetive as possible to catch miniscule "hairs" and fuzz that come off bits of metal that run against each other under the harsh conditions of normal operation.
Occasionally, there will be a piece that comes off a bearing or a gear that is not a part of normal wear and those are the "christmas trees" due to the shape that small bits sometimes make and the "bits with a part number" that are pucker inducing sized.
Procedures are in place to control actions post chip event, and vary from "clean it and carry on" to "SOAP analysis" and "draining and replacement of oil with test flight/hover" to determine following actions.
At the end of the day, the RFM is your first Directive, and thereafter, whatever your Boss has decided in the SOP's.