Each signal is written to the record the first time we detect it, using only data the company had filed by then. Each entry is fingerprinted together with the one before it, so changing or deleting any past entry would break every fingerprint after it. The record is also saved to an external server each day, which keeps its own timestamps.
When we record something in error, we don't remove it: we add a correction that cancels it, and the correction is part of the record too. 35 entries have been corrected so far.
A signal describes a change in a company's reported numbers. It is an observation, not a prediction about the share price and not a recommendation.