One thing in the article struck this Reformed Catholic as in error, and I admit I'm not as well versed in Calvin as some. I quote:
Small focused on three aspects of Calvin’s thoughts on the church that remain relevant today: word and sacrament as central marks of the church, a unified plural ministry of clergy and laity and the communion of congregations.
Now, I'm not sure if this is exactly what Dr. Small's said, or if this was messaged by the reporter, but having attended lectures on Calvin from someone who has made Calvin his specialty (Dr. Charles Partee), I don't believe that is what Calvin actually wrote.
So I checked via Google, and found this information from Dr. C. Matthew McMahon on the site "A Purian's Mind". I won't go through the whole article, but I will list the three Marks as listed there, with supporting Scripture verses:
Mark 1: Sound Doctrine (John 8:31, 47; 14:23; Gal. 1:8-9; 2 Thess. 2:15; 2 Tim. 3:16-4:4; 1 John 4:1-3; 2 John 9-11)
Mark 2: Right Administration of the Sacraments(1 Cor. 10:14-17, 21; 11:23-30)
Mark 3: The Right Administration of Discipline (Matthew 18:17; Acts 20:28-31a; Rom. 16:17-18a; 1 Cor. 5:1-5, 13; 14:33, 40; Gal. 6:1; Eph. 5:6, 11; 2 Thess. 3:14-15; 1 Tim. 1:20; 5:20; Titus 1:10-11; 3:10; Rev. 2:14-16a; 2:20).
Again, not sure if Dr. Small was emphasizing areas of his concern; he is trying to bring back the idea of teaching/ruling elders, or just eliminating areas of Calvin's thoughts that are inconvenient to those who are currently holding power in the PCUSA.