Note: This guide may be slightly outdated. It may be still useful for older releases, but nowadays the vast majority of releases are correctly tagged as WEB-DL (unless it's RARBG/rartv). Protip: prefer looking at file names instead of release names, as they tend to be more accurate.
This is a short cheatsheet to help you determine whether a release from Amazon, Hulu, or Netflix contains the lossless/untouched (as in no further loss of quality compared to what the streaming services provide) video/audio or not. Most newer P2P releases are correctly tagged, but for older releases, it cannot be reliably determined based on the tags alone.
In most cases, non-lossless rips from these services are screen captures (which, when done by professional releasers, should be high quality and contain little to no glitches – see the history section for details), but in some cases they may be simply reencoded from the untouched stream, for example to crop black bars or reencode from a