Imported From: https://issues.scala-lang.org/browse/SI-1219?orig=1
Reporter: @DRMacIver

@paulp said:
A note for when/if this is specified, as of r17315 there is a @tailrec annotation.

Does this still hold true for the current versions?

@nogurenn if you have a look yourself and find out one way or the other, let us know

The word "tail" appears only twice in the SLS

$ rg "\btail" .
02-identifiers-names-and-scopes.md
114:object X { type T = annotation.tailrec }
115:object Y { type T = annotation.tailrec }
117:  import X._, Y._, annotation.{tailrec => T}  // OK, all T mean tailrec
118:  @T def f: Int = { f ; 42 }                  // error, f is not tail recursive

07-implicits.md
107:  else m.add(xs.head, sum(xs.tail))

05-classes-and-objects.md
833:  var tail: LinkedList[A] = null
835:  def this(head: A, tail: LinkedList[A]) = { this(head); this.tail = tail }
841:third one constructs a list with a given head and tail.

The word "tail" appears 7 times, one of which as "tail recursive", and tailrec appears 4 times, used as a weird example of import renaming. The tail recursion in general continues to be unspecified.

The weird example is tweaked in https://github.com/scala/scala/pull/10162/files (Tweaked not for weirdness but correctness: rename on import is higher precedence than wildcard, undermining the point of the example.)

I will supply doc in the annotations section for tailrec and switch. (I also went looking for it.)