http://www.justice.gov.yk.ca/pdf/Final_Transcript_Manual_2014.pdf
The chief concern when producing a transcript is to ensure that it is an accurate
verbatim record of proceedings. Transcribers must certify or attest on each
transcript that it is a true and faithful record of the proceedings transcribed. Since
any transcript may become the basis of a subsequent legal action (such as an
appeal), the necessity for truth and accuracy cannot be over-emphasized.
Because of the need for faithful reproduction, transcribers bear a heavy
responsibility. They must not guess as to the spoken word, but must in all cases
transcribe exactly what was said. A reporter/recorder who transcribes a record
has a duty to not only transcribe accurately, but also to ensure that the oral
comments and testimony of all parties can be heard properly at the time the
proceedings take place.
This is from a manual put out by the government of Yukon - I picked it because the wording is pretty clear. The rules for court transcribing are fairly consistent regardless of which court is being transcribed.