The present research work deals with subtitling errors encountered by simulators and proof-readers. The resultant work is of significant contribution to problem decision makings in the field of quality assessment of audiovisual translation (AVT). The outcome of this paper is the result of accumulated working experience in this domain. The relevant errors are related to syntax, spelling, style, length of sentences, lack of clarity, and gender-related issues. These errors though made by one subtitler who has translated the animation feature film "Pocahontas II" released in 2012, are still typical and therefore a thorough investigation has been done and a set of linguistic rules has been suggested as a guideline for the audiovisual industry. These rules are to be added to the technical and software requirements sent by subtitling companies (such as the number of characters per line, the font, the reading speed per minute, and punctuation). This set of rules helps monitor the quality of the subtitled target text (TT).