What is the ruling on a husband taking back his wife after a single divorce without documenting it in court, and is it valid to document this return after three years?

A husband's reconciliation with his wife after a revocable divorce (ṭalāq rajʿī) before the end of her waiting period (ʿiddah) is valid without the need to renew the marriage contract. As for divorce decreed by a judge, it is an irrevocable divorce (ṭalāq bā’in), except in certain specific cases where scholars have differed, such as divorce due to an oath of abstention (īlāʾ) or the husband's inability to provide maintenance (nafaqah (definition)). In these cases, it is considered revocable by some jurists. To determine the type of divorce and the validity of reconciliation, one must refer to the court. Caution should be exercised in matters concerning marital relations.