in simple passive tense "milk is sold here" but why we say "milk sold here" ?

Question

active voice -- we sell milk here.
passive voice--milk is sold here.

but we call ---milk sold here....why?

Answer 1

A business wants to communicate the service, but not be too wordy on a sign. Stores also post:

Spanish spoken here.
Personal checks not accepted.
ATM inside.
Open weekends.
Visitors welcome.
Open house Sunday.

They just leave out the linking verb and little words like "the.", because they don't add information.

Answer 2

It is a sort of pithy writing, where the meaning is clear with minimum use of words. It is also possible that dropping some words would be a cost saving and space saving technique. Some of us would remember the well-known 'Cold Beer, Sold Here' which rhymes nicely the way it is written, and conveys the meaning very well.
Incidentally, you have written 'why we say' instead of 'why do we say' which is the grammatical form of writing. Maybe the shortening bug has bit you too!

Answer 3

the less words you have on a sign, the cheaper it is to make


bottom line....

Answer 4

It's simpler and understood as well.