Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE table_27914076_1 ( callsign VARCHAR, coverage VARCHAR )

### Question ###
Name the callsign for davao mindanao region

### Accurate SQL ###

SELECT callsign FROM table_27914076_1 WHERE coverage = "Davao Mindanao Region"