as an alternative to Gla
(3AA-15.2.6) if it is desired to emphasize carboxylation
This version of 3AA-17.3 does not use the HTML table format.
3AA-17.3. Substitution on Side-Chain Skeleton
This may use the same convention as 3AA-17.2, with the addition of locant numerals where necessary (see 3AA-16.4), e.g.
4-Carboxyglutamic acid as an alternative to Gla
(3AA-15.2.6) if it is desired to emphasize carboxylation
2,3-Diaminopropanoic acid (3-aminoalanine, see 3AA-15.2.5) 
3,5-Diiodotyrosine Tyr(I2) or Tyr(3,5-I2) if the context does not imply the locants.
3-Nitrotyrosine 