It means: Attention, other dangers with K-25's declaring meaning
After 1974, it was kept as a temporarily preserved sign until 1979, when it was completely replaced with K-25, which features an exclamation mark (!) instead of a vertical line.
Ελληνικά: Κίνδυνος - Παλιά πινακίδα Πδ-1 του Ελληνικού Κ.Ο.Κ.
Μετά το 1974, διατηρήθηκε ως "προσωρινά διατηρούμενη πινακίδα" μέχρι το 1979, όποτε αντικαταστάθηκε πλήρως με την Κ-25, η οποία διαθέτει ένα θαυμαστικό (!) αντί για κάθετη γραμμή.
to share – to copy, distribute and transmit the work
to remix – to adapt the work
Under the following conditions:
attribution – You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.
share alike – If you remix, transform, or build upon the material, you must distribute your contributions under the same or compatible license as the original.