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## About The Pull Request
I finally have the pleasure of killing decl by giving it a new name and
updated handling.
Also abstract_types now have universal support!
Based on:
Baystation12/Baystation12/pull/32114
Baystation12/Baystation12/pull/32687
## Changelog
🆑
code: /decl/ is now /singleton/
code: abstract_type is now on the /datum/ level
/🆑
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