Consider the following comment in a C++ source file:
/* These members are documented with their associated property. */
Should the word property be singular or plural? Each member is associated with exactly one property. However, because there are multiple members, there are multiple properties.
Best Answer
Of your two options, you would use singular otherwise it would not be accurate.
However, it may be clearer to say "Each member is documented with its associated property". I would suggest it would be even clearer to say "Each member is documented with its corresponding property". Corresponding tends to imply a more one-to-one relationship than associated.
Reference 3. associated in a working or other relationship: a bolt and its corresponding nut.