When discussing doctrine with ex-LDS acquaintances, they've mentioned the concept of "milk before meat," presumably based on these words from Joseph Smith's revelation in Doctrines & Covenants 19:
"And I command you that you preach naught but repentance, and show not these things unto the world until it is wisdom in me. For they cannot bear meat now, but milk they must receive; wherefore, they must not know these things, lest they perish" (Doctrine & Covenants 19:21-22).
The individuals I discussed this with said that there are teachings of the LDS church that are considered "meat" doctrines, which Mormons are discouraged from sharing with outsiders or prospective converts until they are ready to receive and understand them. Until that time, they teach them "milk" doctrines" to help them grow and establish their budding faith.
I haven't been able to find a precise list or codification of what constitutes "milk doctrines" as opposed to "meat doctrines." Most of what I've found has been from anti-Mormon teachers and sources, which I won't trust as true until hearing the actual Mormons' side of things.
The Prophet Joseph Smith observed, "If we start right, it is easy to go right all the time; but if we start wrong, we may go wrong, and it [will] be a hard matter to get right." When a proper foundation has been laid, the truth can then flow more freely. The apostle Peter is said to have explained to Clement of Rome: "The teaching of all doctrine has a certain order, and there are some things which must be delivered first, others in the second place, and others in the third, and so all in their order; and if these things be delivered in their order, they become plain; but if they be brought forward out of order, they will seem to be spoken against reason" (ldsliving.com) .
Is there a codified list of what's a "milk doctrine" and what's a "meat doctrine?" Or is it up to the discretion of the individual Mormon to determine what an outsider or prospective convert can or can't "bear?"