An Ortho-Reconstruction is a maneuver changing the side to move but leaving everything else unchanged. It is sometimes used in forward problems (e.g. to put Bl. in zugzwang). In retros it may be used e.g. to overcome a retro-opposition.
Here is an example:
La Genesi delle Posizioni, 1961
11+13. Release the position
Here is an easy example:
32 Personaggi e 1 Autore, 1955
12+12. Black to move. Ortho-Reconstruction
(I.e. reach the same position with White to move in the shortest number of moves.)
Note that "leaving everything else unchanged" may involve castling rights, etc.
[Q] What is the length record with legal position?