Except the first 2 series of maps between 1910 and 1923, the date of edition
is always reproduced on a Michelin map (except for a very few exceptions).
In the majority of the cases it is located in the corner in top on the left
of the sheet, in the right corner for Corsica (sheet 90), in bottom on the
left for some of the series "Etat des routes" and "Routes et
It is necessary to dissociate sheet (the card as such) and covers, because each one has its own code with the date and a rank of edition. At certain periods there can sometimes be a few years of difference between chart and covers.
In the first 2 series, the date is missing, alone the rank of edition is
mentioned, a figure in parentheses, nothing for some of the first edition.
In the example below it is the 4th edition of the sheet number 2
Around 1923, this date printed is "coded", with some other information, in the form of series of figures which we will decipher now.
From 1923 to 1935, one finds 2 groups of figures separated by an indent: (a group of 3 or 4 digits and a group of 2 to 4 digits). 3422-83 In the example below :
first 2 figures give the year; here 1934.
The 2 following give the printing to multiply by 1000; here 22000 copies. (there can be a comma.)
The first (or first 2) after the dash gives the rank of edition; here the 8th edition.
The last (or last 2) give the month of publication; 3 = March.
This chart was manufactured in March 1934,there is the eighth edition, printed in 22 thousand copies.
From 1935, the 2 series of figures are reversed; below: 119-3724
2 first give the rang:11Th edition.
The following give the month: 9 = September.
The first 2 in the second group, the year: 1937
The last 2, the printing: 24000 copies.
This map dates therefore from September, 1937, it is the eleventh edition, drawn in 24 thousand exemplary . For the record, 1937 is the return of marking plain, according to the sheets, 2 markings coexist.
Since 1937 the year is not coded any more, row and pulling disappears, in front of the year can appear "revisée en"revised in, (1937,1938 and 1939), or "Edition Provisoire"Provisional Edition (possibly in summary 1939,1940 and 1941). In 1944 certain sheets are noted only "4" or "4S". And for those having had several editions in the same year, a figure (from 1 to 4) figure under the year.
From 1970 besides the year, the rank of edition returns, but it has been reset with the emergence of a new look. This information still on the cards contemporary.