What are the pros and cons of writing nozzle size vs using e3d style dots on nozzle? e3d uses this scheme to mark the size of their nozzle:

How do I read this scheme? Do we read the second row of dots after completing the first row of dots or we read 1 dot from row 1 and second dot from row 2 the again 3rd dot from row 1 and 4th dot from row 2?
It can be seen here in the nozzle:

Other nozzles usually have size engraved on the hex flat face:

Which one of these is a better scheme to designate a nozzle? is one cheaper to machine than other?
dots
First of all, reading the dot pattern: for all but the 0.15, the total number of dots is read, and there is only 1 dot per side. So a .5 nozzle has dimples on all sides. The only outlier where the dots are not all one next to another is 0.15, which has 2 dots but they are interspaced by one blank side.

0.25
0.3
0.35
0.4
0.6
0.8
0.5 (which was added after the .6 and .8 had already been established)


2 interspaced ones - 0.15, also added after the 0 to 5-dot group had been established.

dots vs. inscription
The inscription is, compared to the dot pattern, much more shallow and can vanish under scratches. Also, the dots are easier to recover from being caked in plastic.
On the flipside, the dot pattern isn't easy to read intuitively, it doesn't follow an easy pattern (the 6 and 2-interspaced-dots are later additions into the setup).