General Forum

Please google it.

Similar to "trolling" due to annoyance of other users. An example of "griefing" could be a user ("griefer") who consistently posts off-topic or inappropriate content in a specific forum thread with the goal of derailing the conversation.

However, "griefing" is mainly associated with online gaming. That is, "griefers" may exploit game mechanics or features in ways not intended by the developers, leading to a frustrating experience for other players.

To answer your question in the way that I look at things (and this is just my personal collection, others opinions may and will vary):

Yes, Leaf was a licensed product, but it was also put out by Donruss.  So I only collect what I consider to be each companies flagship set and all of the errors/variations associated with that set.  In this example, I collect the "beautiful" red 1990 Donruss cards, but not the fancier 1990 Leaf.  Same goes for Fleer and Ultra sets, Topps and Stadium Club, etc.  Just a way for me to focus my collection and funds so I'm not trying to grab everything.  

Do you think error cards were trully accidental, or perhaps some of the manufacturers intentionally created them in their sets, in order to provide some rarity in their products?

Well, it's only an ERR if it's corrected (COR), otherwise it's an uncorrected error UER.  My opinion is that the traditional ERR cards were not intentional as it took effort to correct them. Before computers, I cannot imagine how difficult it would have been to write and proof all the cards - all the stats - all the bio - all by hand.

What if Topps errors in series one, don't realize it and print off the complete set ? Just wondering if they start working on series two , do they go back and print more of series one as needed or are they done printing series one ? Not sure where the correction would take place. Topps 2021 had a Fast Friends card with Bo Bichette and Hernandez but on the back were the names of Bo and Marcus. You know what I mean ? They're not going to keep printing off a set just to correct an error, that doesn't mean it's not an error card does it ? I guess a corrected error card would have less prints because they would be caught before the print run was finished, am I right ?

I wouldn't collect "error" cards simply because they are deemed an error.  I would, however, collect an error card of a card that I would normally collect.  Example:  Let's say I am a Frank Thomas fan so I would naturally collect the 1990 Topps card for him.  I would also want to collect the error of that card (no name on front) and consider it a variation.  However, if I were simply an "Error" card collector and not a fan of the Big Hurt, I would not want to have to shell out the money for that error card (pretty rare) just because it is an error.