[Tagging] Proposing Tag Value bollard=sliding

[Fabian Köster]

Hi all,

we already have the distinction between bollards that are supposed to
always stay in place (bollard=fixed, bollard=flexible) and bollards
that can be moved out  of the way when necessary, with the tag value
indicating which method is used:

bollard=foldable
bollard=removable
bollard=rising

Since a few days in the City of Mainz, Germany we have new bollards
that can be moved out of the way but none of the values above seems to
fit.

The new bollards are very, very robust and intented to withstand acts
of terror with motor vehicles (cars or trucks). When access is given
the bollards are not removed, folded or lowered into the ground but
instead "slide" horizontally. See also the photo here:

https://www.fabian-koester.com/downloads/IMG_20220519_132214.jpg

Of course these types of bollards are not a speciality of Mainz but can
also be found in various other places as a web search for "sliding
bollard" shows:

https://www.google.com/search?q=sliding+bollard

So the term "sliding bollard" seems to also be quite commen for this
kind of bollards and I hereby propose to indroduce this as a new value
to the schema.

Fabian