To answer your question about what they mean by "marked," here you go (from the elder book females are not allowed to read):
Marking Disorderly Ones
1. At times it may be necessary to mark those who display a flagrant disregard for theocratic order though not practicing a grave sin that would result in judicial action. (w99 7/15 pp. 29-31) This could include such things as being grossly lazy or critical or being a profitless talker who is a constant 'meddler with what does not concern him.' (2 Thess. 3:11) It may involve one who schemes to take material advantage of others, indulges in entertainment that is clearly improper, or dates when not legally or Scripturally free.-od p. 150-151.
2. If the disorderly conduct is generally unknown to others and poses no threat to their spiritual wellbeing, usually it is best to handle things through admonition and counsel. The elders should not be hasty in giving a warning talk. However, if the individual does not see the error of his way but continues to be an unwholesome influence, a warning talk may be given to the congregation.-2 Thess. 3:6, 14, 15; w99 7/15 pp. 29-31; w85 4/15 pp. 30-31.
• Example - mark for dating an "unbeliever": The elders should first counsel and try to help a disorderly one. If a person persists in a way that is disturbing and that has the potential for spreading, they may conclude that there would be reason for a warning talk to be given to the congregation.-2 Cor. 6:14; 2 Thess. 3:11,14; w99 7/15 p. 31.
• It may be that an individual is dating not an actual 'unbeliever' but an unbaptized publisher. In such cases a warning talk may not be needed, depending on the circumstances, on the attitude of the Christian, on the level of disturbance to the congregation, and other factors. Nonetheless, if he is dating with a view to marrying someone who is unbaptized, he is not obeying the Bible's counsel at 1 Corinthians 7:39 to marry "only in the Lord" and loving counsel should be given. Elders will use reasonableness and discernment in determining whether a particular situation is sufficiently serious and disturbing to require a warning talk. -od pp. IS0-1S1; w04 7/1 pp. 30-31.
3. If the disorderly one becomes ashamed of his ways and is moved to change, then as elders of the congregation see the adjustment, they can individually decide to end the limitation they have put on personally socializing with him. This will indicate to the congregation that he is no longer marked.