The difference between W9 and W14 signs?

[Primus]

Hello. What exactly is the difference between a speed limit (W9) and temporary speed limit (W14) sign? They seem to serve the same purpose, from what I understand. What is the reason they are both used, sometimes even proximally? 

Thank you. 

[Królik Uszasty]

A new speed limit becomes temporal and a driver is informed about it in witten order O or R-307 before every driventhrough this place. After some time (I think it is 6 months) it becomes permanent speed limit and is listed in a small book given to every driver (WOS - Wykaz Ostrzeń Stałych - List of Permanent Speed Limits). This causes that there are very strict rules for placing temporal speed limits and a bit looser for permanent ones.

[Primus]

I understand. So it is an administrative distinction. Thank you for the information.