Inasmuch as our old supply of temple recommends is exhausted, we are now printing and will soon have ready for distribution, a new stock. This has afforded us the opportunity of making some changes in the form which we deem will be helpful and beneficial to the work. ... To provide a safeguard against forgery you will note we are suggesting that the one who signs the recommend, which means the bishop or the branch president or the counselors, as the case may be, will initial each ordinance for which the applicant is being recommended. ... Upon inquiry we learned that there have been frequent instances where individuals who have not been endowed, and in some cases not presently worthy of a regular temple recommend for ordinances, have been given a recommend to witness a marriage. In place of this practice, which is contrary to the rule of the temple, you will find in these forms the statement "any applicant who has been personally endowed and who is presently worthy to do all ordinances for the dead may witness a temple marriage or sealing."... It is not conducive to temple work to have visitors going through as tourists.
[David O. McKay, J. Reuben Clark Jr., and Henry D. Moyle, circular letter, Nov. 28, 1960, in Anderson, Devery; The Development of LDS Temple Worship, 1846-2000: A Documentary History, http://amzn.to/TempleWorship]