Classification of accession

What are the two (2) classifications of accession?

[1] Accession Discreta (fruits) – the right pertaining to the owner of a thing over everything produced thereby (by internal forces).

[2]Accession Continua – the right pertaining to the owner of a thing over everything that is incorporated or attached thereto either naturally or artificially; by external forces.

[2a] Accession continua over immovables: (i) Industrial (ii) Natural.

[2b] Accession natural over immovables: (i) Alluvion (ii) Avulsion (iii) Change of Course of River (iv) Formation of Islands.

[2c] Accession continue over movables (i) Conjunction and Adjunction (ii) Commixtion and Confusion (iii) Specification.