Shoghi Effendi suggests Baha'i pilgrims to record their notes

"It is very important that the Bahá'ís should accurately record their experiences with the Master and events in the Cause's progress for these things form data for future histories of the Cause. They have not, however, the authority of the revealed Word of the Tablets,..."

(From a letter written on behalf of the Guardian to an individual believer, October 23, 1949: Bahá'í News, No. 228, February 1950, p. 4)

http://bahai-library.com/hornby_lights_guidance_2.html&chapter=4#n1617