BL Choy

> Also, may I kindly and respectfully suggest a different regular expression for extending enumerations? Perhaps something like '[A-Z0-9_]{,30}' or is that too restrictive on character code points? Do we...

> While an unlimited number of extension elements is allowed by the schemas, in reality, the Schematron rule, [Common.Report-2](https://github.com/wmo-im/iwxxm/blob/24e74231c62f142a90437ae392f94309d5bec6b7/IWXXM/rule/iwxxm.sch#L803), limits its use significantly in IWXXM documents as it was designed...

> Only once did the validation tool flagged a METAR message for exceeding the 5K limit. Seems to me this is yet to become an issue. Let's see if we...

> I also like the @mgoberfield restriction '[A-Z0-9_]{,30}', maybe the length should be bigger The template will only be used in enumeration. 30 characters is quite long already: `extension:012345678901234567890123456789`

I would like to go a little deeper into situations where we need unique namespace prefix. ### Case I In a COLLECT example with multiple versions of IWXXM METAR reports...

As there were no further discussions since Aug 2020, may I conclude with the following: 1. IWXXM namespace should be defined in the form `http://icao.int/iwxxm/{version number}`, where: * {version number}...

> Will it be a recommendation for producers of IWXXM data? Or do you mean the Schematron file which is under our control? I will say this is only an...

Thanks Aaron for the article and I am sure we could use this as a basis for representation of weather objects. Note, however, that an originator may only be able...

I agree with your suggestions but how about the latter part of my proposal in #52, viz the use of EPSG:3395 (only) for SIGMET objects until ICAO lifted the requirements...

I think this is not a matter of choice but a regulatory requirement in Annex 3 as mentioned in #52; we only faithfully reflect this in the IWXXM representation for...