Updated doc

README.md

@@ -51,7 +51,7 @@ __Note__: You can use the `lms-metadata` tool to get an idea of the tags parsed
 _LMS_ works best when using the default [Picard](https://picard.musicbrainz.org/) settings, where the `artist` tag contains a single display-friendly value, and the `artists` tag holds the actual artist names. This ensures a cleaner, more organized representation of artist names, when multiple artists are involved.
 
 ### Multiple album artists
-While LMS can manage multiple album artists using the `albumartist` tag, it works better when using the custom `albumartists` and `albumartistssort` tags, similar to how it handles regular artist tags.
+While _LMS_ can manage multiple album artists using the `albumartist` tag, it works better when using the custom `albumartists` and `albumartistssort` tags, similar to how it handles regular artist tags.
 
 __Note__: if you use Picard, add the following script to include these tags:
 ```
@@ -59,6 +59,31 @@ $setmulti(albumartists,%_albumartists%)
 $setmulti(albumartistssort,%_albumartists_sort%)
 ```
 
+### Album track grouping
+The recommended way to group tracks within an album is to use the `MUSICBRAINZ_ALBUMID` tag.
+
+When this tag is not present, _LMS_ will attempt to group them as best as possible:
+
+If the analyzed file contains a disc number and the total number of discs is greater than 1, sibling directories are also scanned to find a matching album.
+Otherwise, _LMS_ will only consider albums within the current directory.  
+
+For an album to be considered a match, the following conditions must be met:
+* Same name
+* Same sort name
+* Same total number of discs
+* Identical 'compilation' flag value
+* Same record labels
+* Same barcode
+
+## Artist image lookup
+The recommended method is to name the file using the artist's MusicBrainz ArtistID. This file can be placed anywhere within one of the scanned libraries.
+
+If no file with the MusicBrainz ArtistID is found, _LMS_ will look for a file named `artist` (or another name configured in `lms.conf`) in the artist's directories. Here's how it works:
+
+1. Identify the artist's directory: _LMS_ selects all albums by the artist using the "AlbumArtist" link and determines the longest common path among them.
+2. Scan for the image: the directory is scanned starting from this common path, moving upwards if needed, until the cover art file is found.
+3. Fallback search: if no image is found, _LMS_ will then search within each individual album folder.
+
 ## Playlist support
 _LMS_ supports playlist files in `m3u` and `m3u8` formats. These playlists are synced during the scan process and are available as public shared playlists.