From the website of the PCA in regards to the "Good Faith" subscription to the Westminster Confessions.
While our Constitution does not require the candidate's affirmation of every statement and/or proposition of doctrine in our Confession of Faith and Catechisms, it is the right and responsibility of the Presbytery to determine if the candidate is out of accord with any of the fundamentals of these doctrinal standards and, as a consequence, may not be able in good faith sincerely to receive and adopt the Confession of Faith and Catechisms of this Church as containing the system of doctrine taught in the Holy Scriptures (cf. BCO 21-5, Q. 2; 24-5, Q.2).
Therefore, in examining a candidate for ordination the Presbytery shall inquire not only into the candidate's knowledge and views in the areas specified above, but also shall require the candidate to state the specific instances in which he may differ with the Confession of Faith and Catechisms in any of their statements and/or propositions. The court may grant an exception to any difference of doctrine only if in the court's judgment the candidate's declared difference is not out of accord with a fundamental of our system of doctrine because the difference is neither hostile to the system nor strikes at the vitals of religion.
Selection from the RPCUS (rest can be found in Gary's post):
Strict subscription does not mean that one must adopt every wording of the Standards as the best explanation of the system of doctrine. Of course, we must be careful with any modification of words seeing that words are the vehicles that convey thought. Moreover, we must be careful not to twist the meaning of words in order to create a different sense than originally intended. This type of perversion was done by the 1972 PCUS General Assembly pertaining to the meaning of the phrase, “containing the system of doctrine.” The General Assembly said with reference to the Standards, “On the other hand, since they are said to contain the system rather than to be equated with it, allowance is made for the possibility that they may incorporate elements which neither belong to it nor are essential to it” (quoted in Morton Smith, How Is The Gold Become Dim, p. 224). The 1972 PCUS General Assembly further stated, “none of us will traduce or use any opprobrious terms of those that differ from us in these extraessential and not necessary points of doctrines” (Ibid.). Even though this wording is in the 1729 Adopting Act, the meaning of the words “extra-essential” and “not necessary points of doctrine” came to be so broadly interpreted that it would embrace non-Reformed doctrine and heresy. It became the agenda of the PCUS to act as if it was committed to the Westminster standards, but functionally it abandoned its foundational tenets. By its own admission, the PCUS in its later days confessed to being a loose subscriptionist denomination.
The doctrines and wording of the Westminster Standards are clear. The RPCUS expects all of its officers to give allegiance to every doctrine of every chapter of the Confession. This doctrinal allegiance applies only to elders and deacons -- not to church members. All that is required to become a member in any church of the RPCUS is to give a credible profession of faith to the church session. In essence, there is nothing extraordinary about the RPCUS’ expectations. We simply believe in subscription to our Constitution. There are undoubtedly some of our Reformed brethren who think we are too narrow because we are presuppositional, theonomic, postmillennial, and limit congregational voting to male heads of households. The RPCUS insists that these particular distinctives are not extraneous doctrines to the Standards; rather, they are the doctrines of the Standards