Nicene and Post-Nicene Fathers, Ser. II, Vol. XIV:
The Canons of the Council in Trullo; Often Called The Quinisext Council.: Canon LXIII

Canon LXIII.

We forbid to be publicly read in Church, histories of the martyrs which have been falsely put together by the enemies of the truth, in order to dishonour the martyrs of Christ and induce unbelief among those who hear them, but we order that such books be given to the flames.  But those who accept them or apply their mind to them as true we anathematize.

Notes.

Ancient Epitome of Canon LXIII.

Martyrologies made up by the ethnics (῾Ελλη νιών) shall not be published in church.

What is condemned is false histories of true martyrs, not (as Johnson erroneously supposes) “false legends of pretended martyrs.”  There have been martyrs, both royal and plebeian, in much later times whose lives have been made ridiculous and whose memory has been rendered hateful to the ignorant people by so-called “histories” which might well have received the treatment ordered by the canon.