[Tagging] Various alt_name values?

moltonel 3x Combo moltonel at gmail.com
Thu Nov 27 14:19:44 UTC 2014

On 27/11/2014, Andy Mabbett <andy at pigsonthewing.org.uk> wrote:
> On 27 November 2014 at 11:59, moltonel 3x Combo <moltonel at gmail.com> wrote:
>> To me, the semincolon scheme as a general solution is a very bad idea,
>> Either the data user forgets to do the split, or he does it when it wasn't
>> the
>> mapper's intent, or litteral semincolons in the data get in the way.
> Could you provide some examples of where each of these scenarios has
> caused problems, please?

The current default rendering is regularly fixing issues with semicolons :
Sure, they fix them. But they keep finding new ones, it's just one
style amongst many, and they probably have more manpower than the
average style.

Searching through an old Ireland extract I have lying around, here is
a sample of values containing ';' that has nothing to do with

note=Legend has it that Fore Abbey has a tree that doesn't burn, hence
the burn=no tag ;)
FIXME=If foot and bicycle can get around this gate; then create such a way
name=McCafferty;s Chemist
source=cadastre-dgi-fr source : Direction Générale des Impôts -
Cadastre ; mise à jour : 2008

And some more examples that can only be considered multi-value with a
good bit of mind-bending :

opening_hours=Mo,Tu,Th,Fr 09:30-16:30; We 10:00-16:30
is_in=Spencer Dock; Dublin; Ireland

Special mention for "seamark:buoy_cardinal:colour=black;yellow" which
is actually just one value (you can't pick out "black" and still have
a meaningfull value).

I don't know of any consumer that implemented semicolon-escapes, so
we're praobably "safe" here.

To be clear, for any "formal multi-value scheme" to really work, it
should be possible to apply it programmatically to all tags, not just
to a manually-curated whitelist (as the recurring osm-carto issues and
the non-multivalue semicolons show).

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