The recording's data is very important for its identification. Many releases contain the detailed data of all included recordings. E.g., all releases of Bear Family Records (and many other labels) contain a discography (see image 1 for example). But now we can't add a part of this data to a recording:
1. Date (except the rare cases of presence of Recording-Work Relationship).
2. Location.
3. Master number.
Besides of this basic data, a recording may be (and often should be!) specified by some other data, taked from a liner note, other sources such as discographies of artist or presse articles, and as a result of listening and/or viewing on a sound editor like Adobe Audition or Sony Sound Forge:
4. Mono or stereo (the last by default).
5. Live or studio (the last by default).
6. Content (e.g. <false start take 2 + take 3> or <composite, takes 4+6+9>, <incomplete take 8>, <take 1 overdubbed>, <take 6 - master undubbed>, <chatter + take>, <studio noise + take 3 aborted> etc.)
7. Net length of sound (silence, chatter, studio noise and false starts - if this/these false starts are not a main content of track - deducted).
8. Sound quality (estimation grade from very poor as <1> to excellent as <5>).
9. Other information (not provided above).
Image 2 is the screen of two tracks opened in Sound Forge. The main sound is the same - recording 'Rock and roll-mops' by Henri Salvador alias Henry Cording and His Original Rock and Roll Boys:
http://boris-vian.net/fr/rock2.html
but two recordings are different (not only by length).
According to the suggested layout (0.0 and 0.1 already present in MB):
Track 1 (above):
0.0. (Length) 2:28
0.1. (ISRC) FRZ035600650
1. 1956-06-21
2. Studio Apollo, rue de Clichy, Paris, France
3. [n/a]
4. 1 [mono]
5. 0 [studio]
6. take
7. 2:24
8. 5
9. [n/a]
Track 2
0.0. (Length) 2:44
0.1. (ISRC) FRZ035600650
1. 1956-06-21
2. Studio Apollo, rue de Clichy, Paris, France
3. [n/a]
4. 1 [mono]
5. 0 [studio]
6. studio noise + take
7. 2:24
8. 2
9. level incorrectly adjusted (amplitude's limitation)

This data (1-9), so far not able to be added in MB, is of great importance for the recording's identification (merge or not) and generally for many users (especially for collectors).