Add best practice for negative examples to style guide

[rjyounes]

E.g., for StreetAddress:

gist:negativeExample "A PO box address or FPO code."

Evolved from the discussion of PR #508.

@uscholdm I don't see a similar issue from you, but if you have submitted one we can close this as a duplicate.

[uscholdm]

Its not a stretch to think of a negative example as an example, so we could get away with jsue using skos:example and highlight the fact that it is a negative example. e.g.

skos:example "Negative example: A fictional character is NOT a person."^^xsd:string ;

I don't feel strongly about it either way.

[rjyounes]

I don't like relying on magic sequences of characters to convey the meaning - I.e., "Negative example." That reminds me of when, before we used skos:example, we had rdfs:comments in the definition prefixed by "EXAMPLE:". This seems to me to defeat the purpose of having specific annotations. That being said, in this particular case it's not such a big deal either way.

[uscholdm]

Aside from thinking that there is nothing magical about negativity, I'm ok with having a separate annotation, but we might as well gather more opinions in case there is a clear preference.

[uscholdm]

@rjyounes Let's bring this to the group. I think it is a reasonable idea.

[rjyounes]

DECISION:

• Don't add an annotation property
• Add to style guide - can add in scope note as "Negative example:"
• E.g., "Negative example: PO Box, FPO code" or "Negative example: PO Box"