Much of older export code has been eclipsed by newer codes like ^value(…action code…)^ allowing access to action code operators the better to define the target object.
Legacy information
Although historically export code did not need, or sometimes did not like, $-prefixes or quoted strings the ^codes have been reviewed in v5.7+ and should behave correctly if you use action code type conventions.
All more reason to review old code and adopt current syntax for all new work.