1- Indicates the type of material. A means ferrous metals, B non-ferrous metals, C ceramics – concrete and… Example A 36 simple carbon steel

2- It can be 1 to 4 digits. It is only a counter and no information can be obtained from it. Example A 36 plain carbon steel sheet. A 105 plain carbon steel forging or pipe

3- M indicates that it also shows the metric standard.

4- The number after the dash indicates the year of creation of the article or its last revision and revision. Example A 36M-97 was last revised in 1997.

5- It can be the letters a, b, … which indicate the number of revisions in that year. Example A 36M – 97b states that in the year 97, 2 times (a,b) were revised.

6- The superscript e (epsilon) indicates that in the last revision, changes have been made to the headline. For example, Note e1: Table 2 was corrected as a headline in 1999.