When a proposal is accepted, even implicitly, no other man may make a proposal of marriage to the same woman if he is aware of the first proposal.

It is forbidden to make a direct expression of one’s desire to a widowed woman while she is in her waiting period.

A proposal is no more than an expression of desire and a promise of marriage; it cannot count as a marriage.
-  Each of the two spouses must be identified in person.
-  Marriage by compulsion is not valid, and each of the two spouses must agree to the marriage.
-  The presence of the woman’s guardian.
-  The presence of witnesses
-  The absence of any reasons that preclude the marriage.