Serial numbers

Table 4 presents the dominant policies used in each country for insuring that serial (version) numbers are always growing. We can find three strategies for serial number management: only incremental, starting with 1 and incrementing 1 by 1; in dotted decimal notation, i.e., the serial number is in the following format: Release.Version (for example 1.01); and date codification (with several variants: using 2 or 4 digits on the letf side for the year, and using 0 or more digits on the right side for the version in the same day).


Table 4: Policies used in the serial number make up (1992, April the 14th)
  Only Dotted Date
  incremental decimal codification
AT many few few
BE none few many1
BG none all none
CH many some few
CS some some some
DE some some many2
DK few some many
ES few none many3
FI few few many4
FR few few many5
GR some many none
HU none some some
IE some none some
IL some few none
IS none none all6
IT some few many7
NL some some many
NO few many8 few
PL few few many9
PT some none many
SE few few many10
SU none all none
TN none all none
UK few few many11
YU all none none



1 The format most used is YYMMDDV.
2 Several different formats are used and there are some zones that join the number 53 (port of domain service) at the left of the date format.
3 Almost all use the format YYMMDDVVV.
4 The format most used is YYYYMMDDVV.
5 The following two formats: YYMMDDVV and YYMMDDV, are the most used ones.
6 All zones use the format YYYYMMDDVV.
7 The format most used is YYMMDD.
8 There are many serial numbers with six zeros between the number and the version (ex. 100000015).
9 The format most used is YYMMDDVV.
10 The format most used is YYYYMMDDVV.
11 The format most used is YYYYMMDVVV.


There were some administrators that seemed to follow no apparent heuristic, at least at first sight, like the following examples: 2147483647 in ``iiasa.ac.at'', 587000483 in ``epfl.ch'', etc. The main reasons causing a regression of the serial number, we have caught, are:

We also found some zones with a negative serial number.