How to understand the fifth paragraph of INTRODUCTION
The fifth paragraph of introduction as below:
When a part 2 standard does not include additional requirements to cover hazards dealt with in Part 1, Part 1 applies.
NOTE 2 This means that the technical committees responsible for the part 2 standards have determined that it is not necessary to specify particular requirements for the appliance in question over and above the general requirements.
Some clauses of the Part II standards may replace or modified Part I requirements, in which case they are implemented directly in accordance with the Part II requirements; otherwise, they are implemented in accordance with Part I.
The part 1 of the standard, clause 24.2, requires that there be no switches on the power supply cord, but in IEC 60335-2-17 standard for electric blankets, switches are permitted on the cord, so the second part of the requirement is followed here.
If the requirements have already been given in Part I and accepted in Part II, there is no need to state them specifically in Part II when setting standards.