(+1 to what Manuel wrote)

For huge features like this that partially can reuse existing objects like ridges, tags on the ways are not really helpful and all tagging should be on relations. If this is type=watershed (which is mostly used in a different sense), but e.g. here for the alpine divide: relation/14461262
Or another type like 'drainage_divide' or 'water_divide' can be discussed / propose.

Hi,
please don't invent new tags just to "silence JOSM warnings". watersheds are being mapped since more than 15 years without the need for such a tag.

These ways are part of a proper relation with an at least documented type. That should be perfectly sufficient to just ignore warnings of an imperfect validator.

You write "used to provide a link for a source:geometry" - but this is exactly the definition of "source_ref".

cited from the wiki: "In contrast to source=*, which holds a description of the source of data, source_ref=* is used to link to an external source of information. "
source_ref=*

"*:link" tags are rarely used and not documented, 'source:geometry:link' isn't used at all up to now.

There are ways with tags like "6 = 4" or "6=5"

"boundary" doesn't necessarily mean "administrative boundary":

boundary=statistical

I'd argue it is a boundary and should have regular boundary tags, no matter what a validator says.

'lanes:bus:backward' already says that there is a lane for buses. Without further tags, there is no reason that it is not 24/7.

The current tagging scheme is with explicit access tags:

access:lanes:backward = no|
bus:lanes:backward = designated|

and, if bicycles share the lane:

bicycle:lanes:backward = yes|

What has been lost? A road that is open at all times doesn't need an additional tag stating this.

Additionally:
- 'busway' is deprecated and shouldn't be used anymore

- 'opposite_lane' only makes sense in combination with a oneway road

- "opening_times" is a key that doesn't exist at all - a bus lane that exists for a limited time would be tagged as
lanes:bus:conditional = 1 @ Mo-Fr 08:00-16:00

Hi,
I wonder what the reason is to use "is:boundary" instead of "boundary"?

Hi & welcome to OSM!
you used many tags here that are not in use in any other place. Please use only tags that are described in the OSM Wiki or are available in the presets of your editor.
This is necessary to make sure that every other user can understand the data.

During the "learning phase" it would be helpful to limit your tags to a smaller area you personally know and not to edit in various points all around the world.

Hi,
could you check the new tags here? Shouldn't it be "construction:railway:etcs" instead of "construction:etcs"?

Please check the history of the objects. Your impression of my edits don't match what I did.

script? automated edit? What do you mean?

The wiki is very clear:
"link to a single Wikipedia article",
"in the primary (local) language"
"a single wikipedia tag is sufficient"

There is only one link here, and there is no need for a language code in the key.

No, there is no duplication done, see
wikipedia=*#Secondary_languages

There is indeed one wrong link added by mistake, I will fix this.

Please read the description of the key. The very first line says "Only provide a link to a single Wikipedia article, which should be to the article in the primary (local) language for the subject"

the value of the wikipedia tag contains the language, it is not repeated in the key.

'year_of_construction' is a common tag. 'contruction_date' (sic!) is not.

Wikipedia manages a full list of all languages of the article. There is no reason to duplicate this list in OSM. The linked article is either in the local majority language or English.