I know scientists have created synthetic bacteria, with a genetic code containing 6 letters instead of 4, with the aim of creating more complex proteins (using amino acids outside of the standard 20+2, the +2 being selanocysteine and pyrrolysine).
Are there any examples of already-known organisms that use more than the 20+2 commonly occurring amino acids, when translating from RNA codons to amino acid sequences using the ribosome? Post-translational modifications would not count, as the ribosome would not be directly responsible for the incorporation of the amino acid into the protein through that method.
Source: 22 proteinogenic amino acids
https://en.wikipedia.org/wiki/Proteinogenic_amino_acid