To think hanging Christmas decorations shouldn't be breech of tenancy?

[aliceinwonderlandforg]

So my grandma lives in a block of multi storey flats which are council property.
Friday this was posted in the lifts
"Please not due to health and safety,tenants are advised not to hang Christmas decorations"
Otherwise it's a breech of tenancy and further action would be taken.
I called and was told this included Christmas trees.
Aibu to think the worlds gone mental?

Il triple check tomorrow.
Hopefully it's just a missed communication somewhere along the lines.
Maybe she thought I meant Christmas tree on landing possibly

What was the outcome???