Give the banner a name on an anvil.
Place your named banner somewhere.
Break it.
Collect it again.
The banner don't have it's name anymore.
Related issues
Comments
kumasasa
MC-64795
Banners loosing their names.
Resolved
Duplicate
0
kumasasa
migrated
(Unassigned)
Unconfirmed
Minecraft 14w31a
Retrieved
Every block does that.