You must think carefully about whether you want or need to make a disclaimer. If your registered design contains features e.g. pattern(s) or colour(s) which do not relate to your design, then you should consider the use of a disclaimer.
Equally, if your design only relates to a part of the product, then you should consider whether or not to limit the scope of your design to that particular element.
Disclaimers and limitations can play an important role in any dispute where you want to enforce your rights against someone who is copying your design, or if there is any dispute about its validity.