What mean "**kwds" in the option of a command?

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Im trying to figure what are the options of the command "line", then I used the help command "line?" for a brief description of it structure and usage.

In the position for option it says "**kwds", I figure that these are some kind of abbreviations but I dont found on the search of the documentation of sagemath something about this, can someone explain to me or leave a link to this information? Thank you.