Marking Coins -- Do You See Marks Again (Later Batches?)

I don't mark the coins I search, but I have run across some marked coins while searching half dollars. I've seen a variety of marks (black X, red /, black /, black star, black "NO", etc.), but the frequency of the marks is very low. I don't tend to see groups or batches of marks either in rolls or boxes. Since these aren't my marks, I'm not sure if the ones I find are from a single person or from several searchers.

I tend to get my coins from Bank of America and dump at local credit unions, so I'd be interested to know how often these systems mix and if I search the same coins. But definitely NOT interested enough to actually mark them. Can't say I'm a fan of that practice.

I marked about 300 coins per box for about 5 boxes on the rims with black permanent marker and have not seen them, and its been over a year. I search anywhere from 4-8 boxes of halfs per week.

Never marked the coins themselves, but I do put a little tick mark, out of the way, on the roll/wrapper. You would know if you came across them again, but no one else would even notice.

Three years ago I marked 1,000 halves with a permanent marker before depositing them in my town. The next week my order of 1,000 halves arrived in fresh MWRs and almost half of the halves had my mark. After this I stopped ordering from this bank. After two years of not ordering from this bank, I ordered halves two times and neither found my marked coins nor any silver coins.

Three years later I received one of my marked halves in a box I picked up in a town 6 hours away. The box contained 2 silver coins. What did this tell me? Not much.

I am not a fan of marking halves. I have found several really nice Cu-Ni clad halves with a mark or two or three or four (some CRHers purposely keep marking the same coins) from the same or separate CRHers. If these nice coins had not been marked, then I would have kept them. I know acetone would effectively remove most the mark, but not all.

Again, I am not a fan of marking coins.

WM, in my case I picked up 1,000 halves at one branch, marked them, and deposited the marked halves at a different branch of the same bank in town. In my town there is only one coin courier. As a result, all coins from all the banks in town are processed at a single facility no matter where the coins were deposited. I believe the coin courier in my town, as well as most others, practices "first-in, first-out", which is why I initially (the week after depositing my marked coins) received many of my marked coins, but two years later received none of my marked coins.

Haven't done that many halves to say other than last ten rolls had three different markings, kinda knew it was a skunk. When I started CRHing cents and nickels I would do codes, birth year, then different color markers, then for two years wrote numerical day of year(2colors), on those coins set aside for further study, usually @ 100 of each box. This was done from 2013 to mid 2016 when I switched to a single black line across the coins. I have searched over 750,000 LMC's and about 100,000 Nickels to date. Only ONCE have I found my marker coin. That was in a pickup of just a few rolls from the main branch of my other account bank( not where I get the boxes) it wasexactly two weeks after the dump in another branch bank. Apparently the banks roll their own when needed. I've since stopped dumping there. All my dumps are picked up and go to some Brinks facility, but I've never seen another marker. I do it now just for grins, also if I see it again, I've already checked it out!