This is quite a long message, so take your time…
Thank you so much for replying to one of my many messages about how we were not sure what source you were using. We were getting worried about your edits because of your delay in replying to the messages I have sent, asking for additional comment. I take it that you were using Greek law ΦΕΚ Β 319/23.7.1963, which is not in copyright as legislative texts are exempt. However, it is important to take later developments on the road network into account, especially of the realignments and new motorways.
Thank you also for showing interest in trying to untangle the mess that is the Greek road network. If you are new to me, I have been to the country many times before joining OSM, and I started taking the road system seriously back in 2013 when a user in SkyscraperCity, ea1969, confirmed to me that the provincial road numbers had a numbering system (http://www.skyscrapercity.com/showthread.php?p=103224934): the legislative source was ΦΕΚ 47 Α/8.2.1956. My subsequent research confirmed that such a system still exists, according to regional legislation such as ΦΕΚ B 1866/14.09.2007, ΦΕΚ B 2227/20.11.2007 and ΦΕΚ B 1932/26.9.2007 (all exempt from copyright under the 1993 law).
I am still in touch with ea1969 as user Antje on SkyscraperCity: you should, in your free time, browse through the thread at http://www.skyscrapercity.com/showthread.php?t=441395, from page 71, to see how I’ve and other have been trying to figure out the current state of the network. If you do have questions for ea1969, please do post a message there. We have a general shortage of people who treat the Greek road numbering system with as much care as I do.
Indeed, I was not the first one to use National Road numbers on OpenStreetMap, but when I started taking the matter seriously the progress on OSM was very patchy, and not as many villages were connected with tertiary roads as they are now. At the time there were very little tangible evidence to prove where the National and Provincial roads were, and it was only with me that progress on mapping the road network really stepped up. The work is still pretty much in progress, as I am still doing in depth research into the situation.
I must warn in advance that the road numbering system in Greece is a nightmare, even though that national road numbers do appear in other maps. I currently live in the UK, whose road system is so well organised that there is little dispute there, but in Greece much of the road system is based on destinations with road numbers making occasional appearances (if they are in the right places, that is).
All the edits I have done to this point have been in good faith, based on what I have got so far. There is still obviously a lot to be done to get to the bottom of this but I am hoping that the outcome will be the most complete road map of Greece, something a lot better than others. This is why OSM mappers should not give up trying.
In respect of the military roads, I have merely complied with the guidelines at http://wiki.openstreetmap.org/wiki/Highway:International_equivalence (scroll to Greece), but if you complain that they are not worthy of primary route status then that current guideline is awfully wrong. On the other hand I’ve seen national roads not to always be a four-or-more-lane divided highway (at least two lanes per direction), particularly with the EO3 between Eleusis and Thebes.
Despite the complexity of the situation, OpenStreetMap is unable to suggest that the road numbering system be ignored and banned from the database because they still appear on many road signs: plus, road numbers are a fact of life in nearly every country.
Therefore, I am advising that we both halt the road numbering edits (except fro the most critical ones) until we replace the current guideline, to which I was merely complying with. If merely complying with the guideline leads to undesirable results then it is clear that the guideline in question is now no longer working as I have expected. The proposed replacement is at http://wiki.openstreetmap.org/wiki/User:Amaroussi#Greek_road_hierarchy_review.
Also, I speak English as a matter of logistical convenience because of me dealing with many countries, and so to get as many people to understand what I am trying to say.