As a user that has their edit reverted by Automoderator and is sent a talk page message, they should see the preferred formatting for their wiki in the signature on the talk page message.

Notes:

In T355930#10100114, @Trizek-WMF wrote:

Using ~~~~ allows the signature to follow the standard defined by the wiki.
@Kgraessle added the dashed with a space: -- ~~~~ This is what Turkish Wikipedia uses.

The usage of the two dashes is also defined per wiki, but not part of the ~~~~. Of course, it differs from wiki to wiki with a global trend of just ~~~~.

No dashes ~~~~ for Indonesian WIkipedia, French Wikipedia and English Wikipedia (I think English used to have -- ~~~~ IIRC ).

Two dashes but no space --~~~~ is implemented at Chinese Wikipedia, German Wikipedia and Japanese Wikipedia

It would be nice to use the default format defined for each wiki. :)

In T355930#10102561, @matej_suchanek wrote:

DiscussionTools implement that using the discussiontools-signature-prefix message. I also found sig-text (core) and wikieditor-toolbar-help-content-signaturetimestamp-syntax (WikiEditor (2010)).