Meaning of ! (exclaimation point) when optimizing cameras?

[Mycobiont]

I'm sure it indicates some sort of problem in my model, but it might help to know what problem to look for... so just what does the exclamation point mean in

Optimizing point cloud...
adjusting: xxxxxx!xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx 0.569732 -> 0.517

also I think I've seen cases where the last x was followed by a '-' Does that have some meaning too?

Thanks!

[Mycobiont]

I've run into these again and am still wondering what they indicate?  While my first message on this question is old, there are 400 reads, which suggests to me that I'm not the only one to wonder.  Any clarification would be appreciated!

Thanks!

[Alexey Pasumansky]

Hello Mycobiont,

Exclamation mark or minus sign means that optimization iteration has been skipped due to some reasons, so it's not an indication of any issue.