What does an FT8 signal report of +3 mean?

In the FT8 digital mode, signal reports are fundamentally different from the traditional analog RST (Readability, Strength, Tone) system. Instead, FT8 software calculates a direct measurement of the Signal-to-Noise Ratio (SNR) in decibels (dB). A report of +3 indicates that the received signal is 3 dB stronger than the background noise floor. This calculation is standardized across a 2.5 kHz reference bandwidth, which is the typical audio passband of an SSB receiver. Distractors often try to trick you by referencing analog S-meter readings. Reports like "S3" or "3 dB over S9" apply to traditional AM/FM/SSB voice communications, not the automated SNR calculations used in weak-signal digital modes like FT8.