Recommended precaution is a fiqh

Fiqh

Fiqh is Islamic jurisprudence. Fiqh is an expansion of the code of conduct expounded in the Quran, often supplemented by tradition and implemented by the rulings and interpretations of Islamic jurists....

 term, prominently used by Shi'a marja

Marja

Marja , also known as a marja-i taqlid or marja dini , literally means "Source to Imitate/Follow" or "Religious Reference"...

s when giving fatwa

Fatwa

A fatwā in the Islamic faith is a juristic ruling concerning Islamic law issued by an Islamic scholar. In Sunni Islam any fatwā is non-binding, whereas in Shia Islam it could be considered by an individual as binding, depending on his or her relation to the scholar. The person who issues a fatwā...

s.

When Shi'a marjas give fatwas, they sometimes are not sure about the legality of some issues. In those cases, they recommend that the follower of the marja refrain from the act, in case it would indeed be haram

Haraam

Haraam is an Arabic term meaning "forbidden", or "sacred". In Islam it is used to refer to anything that is prohibited by the word of Allah in the Qur'an or the Hadith Qudsi. Haraam is the highest status of prohibition given to anything that would result in sin when a Muslim commits it...

. This is in contrast to the general term Mustahabb

Mustahabb

Mustahabb is an Islamic term referring to recommended, favored or virtuous actions.-Definition:Mustahabb actions are those whose status of approval in Islamic law falls between mubah and wajib...

, where people voluntarily do or refrain from doing actions that they know they are not obliged to.

As example:

It is a recommended precaution that even a child should not be made to sit in the toilet with its face or back facing Qibla

Qibla

The Qiblah , also transliterated as Qibla, Kiblah or Kibla, is the direction that should be faced when a Muslim prays during salah...

. But if the child positions itself that way, it is not obligatory to divert it. http://www.rafed.net/books/other-lang/masael-e/masael-e02.html