system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: What does "patent pending" mean, practically? If the patent has still not gone through couldn't someone still copy the invention?
gpt
I believe that patents can provide legal protection from the date they were *filed*, meaning any infringement could be sued retroactively. It's like saying, "We can't sue you now, but will be able to in the near future."