IMS selectors do not have a display mode (and the viewing groups have changed)

[DavidGrant-NIWC]

IMS selectors by definition are independent of the display mode / category

For instance the diamond pattern does not participate in a display mode, and it doesn't use the indicated viewing group:

[kusala9]

Delete table (is it enough just to define the DIAMOND1 pattern and link to the shallow water pattern? Presumably we need to describe in overview the IMS selectors as well, or is it better to delete these specifics from S-98 Annex C and just point the implementer at the IMS mechanism definitions - on the basis that if they correctly implement the PC then these will all be added to the portrayal? What else remains to be defined for an implementer?

[DavidGrant-NIWC]

There is nothing the implementer needs to do; the IMS are implemented in the S-101 PC using the Part 9 model (as viewing groups).

Useful guidance S-98 Annex C could provide:

• Viewing groups should be combined when present in multiple catalogs (it shouldn't be possible to have the vg off in one product and on in another).
  • Also applies to versions of a PC for a given product.
• Some selectors should be tied to existing functionality in the ECDIS (e.g., update review).
• All viewing groups should be tied to their S-52 equivalents (dual-fuel display should have consistent presentation).
  • In most cases the viewing groups are the same, but due to remodeling in S-101 there are some differences.