According to OLF helideck manual section 5.5.5, section 5.7, section 5.11.2 and section 5.11.6, marking of the various JET A-1 samples is required.
Helifuel AS provides you with the labels you need.

The various Helifuel labels are as follows:

– HF10742; 4L JET A-1 Sample

– HF2272; JET A-1 Tank Status

– HF2271; Not Approved fuel