The correct spelling is well known. A well known author or a well-known company (the hyphen is optional).
The opposite of compulsory (compelled) would be voluntary or optional.
For something to be optional, it means the availability of choice/choices, to have alternatives. The opposite of optional is mandatory, compulsory, required.
No part of the writing process is optional.
recommended but optional
The only way is Booth, meaning a light structure for the sale of goods or for display purposes
Ross Boothe has written: 'Boothe genealogy'
boothe
Powers Boothe's birth name is Powers Allen Boothe.
Parisse Boothe's birth name is Parisse Ashley Boothe.
James Boothe is 5'11.
Clare Boothe Luce's birth name is Boothe, Ann Clare.
Parisse Boothe is 5' 9".
Newton Boothe is 5' 11".
Armistead L. Boothe died in 1990.
Powers Boothe was born on June 1, 1948.
Ken Boothe was born on 1948-03-22.