Aliasing beanie → beanie_(disambiguation)
Link to alias

Reason:

three main types of Beanie.
https://en.wikipedia.org/wiki/Beanie says
"* Beanie (seamed cap), in parts of North America, a cap made from cloth often joined by a button at the crown and seamed together around the sides.

• Beanie, a knitted cap, in British, Australian, South Africa and parts of Canada and the United States (also known as a toque)
• A type of helmet" (helmet article says "often called 'beanies', 'brain buckets', or 'novelty helmets'")

1st type wikipedia article https://en.wikipedia.org/wiki/Beanie_(seamed_cap)
(including Propeller beanie which e621 tag is propeller_hat,
13 uploads tagged with both propeller_hat and beanie)

2nd type Wikipedia article https://en.wikipedia.org/wiki/Knit_cap ,
BUT how do we tell if a hat for cold weather is knitted or seamed?
winter_hat could be better tag. (31 uploads tagged with winter_hat)

So how about separating beanie into
1) winter_hat
and
2) propeller_hat (I checked https://commons.wikimedia.org/wiki/Category:Propeller_beanies and none of them seem adequate for cold weather)
and
3) that helmet type (wikipedia 3rd type) (maybe animal_helmet could imply to novelty_helmet ?)

Some other tags that could alias to winter_hat

• tuque (one upload)
• snow_hat (2 uploads)
• wool_hat (2 uploads)

Wikipedia article includes "A knit cap with ear flaps is often called a bobble hat, toboggan, or sherpa."

So sherpa_hat tag (51 uploads) could IMPLY to winter_hat

re: "bobble hat". I've seen lots of winter hats with bobbles but NO ear flaps.
example: post #904050

Knit cap Wikipedia article also says "British bobble hat
A bobble hat or bobble cap is a knit cap that has a yarn "bobble" or pom-pom upon its top"

(Have bobble_hat imply to winter_hat ?)

EDIT: The tag alias beanie -> beanie_(disambiguation) (forum #258147) has been rejected by @NotMeNotYou.

Those poof balls on the beanies are called bobbles? Huh, neat

It's also an enemy) from Mario & Luigi.

EarthFurst2 said:
...
1st type wikipedia article https://en.wikipedia.org/wiki/Beanie_(seamed_cap)
(including Propeller beanie which e621 tag is propeller_hat,
13 uploads tagged with both propeller_hat and beanie)

2nd type Wikipedia article https://en.wikipedia.org/wiki/Knit_cap ,
BUT how do we tell if a hat for cold weather is knitted or seamed?
winter_hat could be better tag. (31 uploads tagged with winter_hat)
...

Oh, I guess if hat is a beanie with visible seam,
could be tagged as Beanie_(seamed_cap)
(and maybe also with winter_hat if apparently worn for warmth)

The tag alias beanie -> beanie_(disambiguation) (forum #258147) has been rejected by @NotMeNotYou.