Optional options as nullable record

You can get a little more info by using #shared as your source in a blank query.  Convert that to a table and then filter to and click on the function of interest.  In the case of Folder.Files(), the optional parameter is "PreserveLastAccessTimes" and accepts true or false.

Here is the query I used to get to this function, if you want to see for yourself.

let
Source = #shared,
#"Converted to Table" = Record.ToTable(Source),
#"Filtered Rows" = Table.SelectRows(#"Converted to Table", each ([Name] = "Folder.Contents" or [Name] = "Folder.Files")),
Value = #"Filtered Rows"{1}[Value]
in
Value

Regards,

Pat