add condition: year < 2000

As per @georgd here:

At somoe places, years should be formtatted with two digits if year < 2000 and with four digits otherwise. Am I right in assuming that that’s not possible? At least I haven’t found it in the documentation. It’s a requirement that I met in various (legal and non-legal) styles already, especially when dealing with EU sources.

I think that sound like a reasonable suggestion. Other opinions about this? Anyone else has seen that requirement before? If we add this: Perhaps it should be done in a not so specific way. Rather than if after-2000 perhaps something like "if date-range="1900-1999" which would be adaptable to other requirements.

[bdarcus]

We need a solution that works in the context of xml processing tools. One question I was looking to find an answer for recently, but did not, was whether attribute value order is preserved in XML. Attribute order itself is NOT.

Anyway, more options:

date-range-key='issued' date-range-values='1900-2000'

… or, I think the best balance of flexibility, conciseness, and processing and validation rigor:

date-range-key='issued' date-range-start='1900' date-range-end='2000'
date-range-key='issued' date-range-end='1900'

[bdarcus]

The cool thing about rnc is it’s so easy (unlike json schema) to test out the validation logic.

start = element style { cs-test+ }

cs-test = element test { test-dates | test-names }

test-dates =
  attribute tested { "issued" },
  attribute date-test { text }

test-names =
  attribute tested { "author" },
  attribute name-test { text }

<?xml version="1.0"?>
<style>
  <test tested="issued" date-test="foo"/>
  <test tested="author" name-test="bar"/>
</style>