[David O. McKay, Hugh B. Brown, N. Eldon Tanner, and Joseph Fielding Smith]
From time to time we receive requests from couples who desire to be married by civil ceremony before traveling from their home to the temple to have the sealing solemnized. For your guidance we are pleased to tell you that the ruling is that where couples are married by civil ceremony they should normally not be recommended to the temple until after a year or very near that period of time has elapsed since the civil ceremony was solemnized. Occasionally we receive requests for exceptions to this ruling, the reason given being that the parents of one or both of the contracting parties are non-members and are desirous of witnessing the civil ceremony. In such cases we have, as a general rule, granted permission. It should be understood, however, that this permission must be obtained in each instance from the First Presidency before authorization may be given. Where parents of the couple to be married are members of the Church but not active or qualified to receive temple recommends, we have not felt to grant exceptions to the general rule that the marriage should be performed in the temple in the first instance.
[David O. McKay, Hugh B. Brown, N. Eldon Tanner, and Joseph Fielding Smith, circular letter, July 6, 1966, in Anderson, Devery; The Development of LDS Temple Worship, 1846-2000: A Documentary History, http://amzn.to/TempleWorship]