The label 'phosphate' is misleading in CHEBI

[cmungall]

In CHEBI:

• The string phosphate ion means an inorganic molecule like (P4O](https://www.ebi.ac.uk/chebi/searchId.do?chebiId=CHEBI%3A18367 )[O-]P([O-])([O-])=O
• The string phosphate is a more complex molecule, typically organic
  • Def: "Salts and esters of phosphoric and oligophosphoric acids and their chalcogen analogues. In inorganic chemistry, the term is also used to describe anionic coordination entities with phosphorus as central atom.".
  • 1000s of subclasses, including complex molecules like https://www.ebi.ac.uk/chebi/searchId.do?chebiId=CHEBI:64289 [H][C@]1([C@@H](C)Nc2ccc(C[C@H](O)[C@H](O)[C@H](O)CO[C@H]3O[C@H](COP(O)(=O)O[C@@H](CCC(O)=O)C(=O)N[C@@H](CCC(O)=O)C(O)=O)[C@@H](O)[C@H]3O)cc2)[C@H](C)Nc2nc(N)[nH]c(=O)c2N1C

I think this is confusing terminology and liable to mislead people into using the wrong term. "phosphate" sounds like the protonation-agnostic form of "phosphate ion".

The confusion is reflected in the definition of phosphate, which is effectively two definitions. How is a curator meant to pick which one to use? The definition also says it's a salt and an ester, but it's not classified as either.

The confusion is also reflected in the mappings. For example, it maps phosphate to C00009 in KEGG, which is clearly and unambiguously H3PO4 and has a mol file.