Yosef Karo, Translation:Shulchan Aruch — Yoreh Deah 402
“ And he counts from the day of death and not from the day [that he received] the message. Therefore, if he received the message about his father or mother after 12 months, he only needs to observe a single day, even for the decrees of 30 days.Seif 2:One who receives a shemuah rehoka does not need to observe all of the rites of mourning, rather, it is sufficient for him to take off his shoes, and he does not need to wrap [his head] nor to overturn his bed, and he is permitted to perform work, to bathe, to anoint, and to have sexual relations, and to study Torah. ”
