I discovered by playing around that
Text[DisplayForm@SubscriptBox["λ", "k"]]
produces the same result as
Text["\*SubscriptBox[\"λ\", \"k\"]"]
and, further, that the \*
is essential. This finding suggests that \*
means DisplayForm
when inside a string. After more playing around, I found that
Text["\!\(\*SubscriptBox[\"λ\", \"k\"]\)"]
produces the same result, but only if you have the bang and the parens, that is, that \!
and \(
+\)
are both necessary; either construct alone will not work.
Where can I find the documentation for this magic? I don't know what to search for because I don't know what these kinds of constructs are called.