A more thorough explanation:

An alternative writ of mandate, also known as an alternative mandamus, is a court order that directs a party to either perform a legally obligated action or cease an activity at a specified time or show cause before the court as to why the party has not done as required or should not be ordered to do so. This type of writ is typically used to state allegations of a complaint against a governmental agency, corporation, court, official, or other public authority.

For example, if a citizen believes that a government agency is not fulfilling its legal obligations, they may file a complaint and request an alternative writ of mandate. The writ would then direct the agency to either perform the required action or show cause as to why they have not done so.

Alternative writs of mandate are unique because they may be made without completing a trial. They are deemed necessary when the actions or inaction of government bodies or corporate officials are so inappropriate or egregious that immediate, emergency action must be taken by the legal system.

Another type of writ of mandamus is the peremptory writ of mandate, which is similar in form to the alternative writ but does not require the party to show cause why they have not done as commanded.