To provide a write-once optical recording medium, which has rewritable properties in addition to the write-once properties.

The optical recording medium has a recording layer with at least a first recording sublayer (R1) and a second recording sublayer (R2) for recording information marks by alloying the material of at least the first and second recording layers (R1 and R2). The material of at least the first and second recording layers (R1 and R2) is chosen such that the alloyed material is a phase-change material adapted for recording additional data as phase change of the alloyed material.