I'll talk here about only Kannada language movies.
Kannada movies especially Upendra’s directed movies have unique posters that are only one alphabets or symbols.
A(1998)
This movie changed the Kannada film industry for ever . This was something new in Indian cinema at that time. It was the biggest blockbuster and industry hit in Kannada Film industry back in 1998.
The photo shows a metaphor.
Others include
Shhh!(1993) - An horror mystery thriller. It is considered as the best horror mystery thriller in Karnataka. The poster shows a skull with silent posture of Kannada alphabet.
Upendra (1999) - the unique poster shows the main character with three main female leads.
UI (2024) - Vishnu naama/ Vishnu Tilaka and underside of a Horse hoove.