https://secure.byond.com/docs/ref/#/proc/initial does not describe the ability to use initial() on types which was added in 137997
Code Snippet
/datum/something
var/test = "hi"
/world/New()
var/datum/something/type = /datum/something
world.log << initial(type.test)
This behaviour is actually really helpful and its a shame that its completly undocumented in the reference
Suggested addition to the reference
This can also be used to fetch the original compile-time value of a variable on a type using the following syntax
var/obj/sword/type = obj/sword
usr << "[initial(type.name)]"