((p "Each zettel is given a unique identifier." " " "To some degree, the zettel identifier is part of the metadata." " " "Basically, the identifier is given by the " (a (@ (href . "00001005000000")) "Zettelstore") " software.") (p "Every zettel identifier consists of 14 digits." " " "They resemble a timestamp: the first four digits could represent the year, the" " " "next two represent the month, following by day, hour, minute, and second.") (p "This allows to order zettel chronologically in a canonical way.") (p "In most cases the zettel identifier is the timestamp when the zettel was created.") (p "However, the Zettelstore software just checks for exactly 14 digits." " " "Anybody is free to assign a " (@L (@H "“") "non-timestamp" (@H "”")) " identifier to a zettel, e.g. with" " " "a month part of " (@L (@H "“") "35" (@H "”")) " or with " (@L (@H "“") "99" (@H "”")) " as the last two digits.") (p "Some zettel identifier are " (a (@ (href . "00001006055000")) "reserved") " and should not be used otherwise." " " "All identifiers of zettel initially provided by an empty Zettelstore begin with " (@L (@H "“") "000000" (@H "”")) ", except the home zettel " (kbd "00010000000000") "." " " "Zettel identifier of this manual have be chosen to begin with " (@L (@H "“") "000010" (@H "”")) ".") (p "A zettel can have any identifier that contains 14 digits and that is not in use" " " "by another zettel managed by the same Zettelstore."))