Writ of Habeas Corpus a civil case number and assign it to the judge assigned to the pending writ with the lowest case number. "To have the body"—that's what the Latin phrase habeas corpus means in English.Who Should Use This Form. You should use this form if. How long do you have to file a writ of habeas corpus? Find out what this deadline is and what Florida post-conviction motions can extend this time period. Habeas corpus is used to challenge the legality of the detention or restraint of a person and to obtain the person's prompt release. The "Great Writ" of habeas corpus is a fundamental right in the Constitution that protects against unlawful and indefinite imprisonment. Latin for "that you have the body. Lucie Counties); the West.