IEC 60717:2012 pertains to capacitors and resistors that feature unidirectional wire terminations, specifically designed for use in electronic equipment.
It outlines a method for determining the space requirements for capacitors and resistors with unidirectional wire terminations.
NOTE: Instead of measuring the actual space, it may be adequate to verify that a component fits within the maximum space for which it has been designed. This can be accomplished using fixed gauges.