And how do they relate to “everyday” Presbyterians? Again, I don’t know either and would interested in learning.
What do you consider to be an "everyday Presbyterian"?
The OPC split from the liberal Northern Presbyterian Church in the mid 1930s. The PCA split when the Northern and Southern churches merged in the early 1970's.
The merged church, PC(USA) is very liberal and dying on the vine. They are the ones ordaining homosexuals.
From a doctrinal perspective, conservative Presbyterians, all hold to the Westminister Confession. The OPC and PCA differ in the way they evolved over time, having spit from liberal bodies at different times and in different parts of the country.
The ARP allows women to serve as deacons, but not elders or teaching elders. The PCA and OPC don't. I don't know enough about the RPCNA to comment.
What does this mean to "everyday" Presbyterians? Members can move between the OPC and PCA, as well as the ARP with no problem. Pastors can as well.
I have been a member of the PCA, ARP as well as the United Reformed Church of North America (which is Dutch Reformed). The URCNA holds to some documents called the Three Forms of Unity and when I joined I could not distinguish between them and Presbyterian doctrine. I have actually been in several Presbyterian Churches that use Question One of the Heidelberg Catechism, a Reformed Church document, for responsive reading.
Q. What is your only comfort in life and in death?A. That I am not my own,1 but belong— body and soul, in life and in death—2 to my faithful Savior, Jesus Christ.3 He has fully paid for all my sins with his precious blood,4 and has set me free from the tyranny of the devil.5 He also watches over me in such a way6 that not a hair can fall from my head without the will of my Father in heaven;7 in fact, all things must work together for my salvation.8 Because I belong to him, Christ, by his Holy Spirit, assures me of eternal life9 and makes me wholeheartedly willing and ready from now on to live for him.10
1 1 Cor. 6:19-20
2 Rom. 14:7-9
3 1 Cor. 3:23; Titus 2:14
4 1 Pet. 1:18-19; 1 John 1:7-9; 2:2
5 John 8:34-36; Heb. 2:14-15; 1 John 3:1-11
6 John 6:39-40; 10:27-30; 2 Thess. 3:3; 1 Pet. 1:5
7 Matt. 10:29-31; Luke 21:16-18
8 Rom. 8:28
9 Rom. 8:15-16; 2 Cor. 1:21-22; 5:5; Eph. 1:13-14
10 Rom. 8:1-17
Here is one article: Differences between the OPC and the PCA that may help.
PAR35 may be able to provide some insight as to the accuracy of the link, as well as my above blatherings.