Practice Directions do not have the same status as the Civil Procedure Rules themselves.
Sometimes the Practice Directions are misleading. Sometimes they are simply wrong (eg KU (A Child) v LCC  EWCA Civ 475).
One example of the Practice Directions being misleading/wrong is in relation to the issue of setting aside a Default Costs Certificate (DCC).
PD 47 para.11.2(3) states:
“As a general rule a default costs certificate will be set aside under rule 47.12 only if the applicant shows a good reason for the court to do so and if the applicant files with the application a copy of the bill, a copy of the default costs certificate and a draft of the points of dispute the applicant proposes to serve if the application is granted.”
To understand why this is incorrect, one needs to look back at CPR 47.12 itself:
“(1) The court will set aside a default costs certificate if the receiving party was not entitled to it.
(2) In any other case, the court may set aside or vary a default costs certificate if it appears to the court that there is some good reason why the detailed assessment proceedings should continue.”
It is immediately obvious that CPR 47.12(1) and CPR 47.12(2) are separate and self-contained provisions.
CPR 47.12(1) is a mandatory provision. Where the receiving party was not entitled to a DCC, the court will set it aside. There is no discretion for the court to exercise. There is no requirement for a “good reason” to be shown.
The correct position is set out in Cook on Costs 2022 at 28.35:
“The court must set aside a default costs certificate if the receiving party was not entitled to it according to CPR 47.12(1).”
Equally, Friston on Costs correctly summarises the position at 43.155:
“Setting aside as of right
If the receiving party was not entitled to the default costs certificate, then the court has no option but to set it aside.”
If an application is made to set aside a DCC under CPR 47.12(1), it must further be questionable as to whether PD 47 para.11.2(3) is correct when it says such an application must be supported by draft points of dispute. If there was no entitlement to a DCC (because, for example, there was no order for costs), why would it be necessary or appropriate to file draft points of dispute with the application?
On the other hand, CPR 47.12(2) is an entirely different provision that deals with the situation where the receiving party was entitled to the DCC. In this case, the paying party needs to provide a “good reason” to have the DCC set aside.