What documents are needed for DTV visa application with a friend's address in Thailand?

The user is seeking advice on the DTV visa application process while planning to stay at a friend's condo in Thailand. They inquire about the necessity of an invitation letter and other required documents, noting difficulties in obtaining documentation from their friend's employer. Community comments indicate that simply having an invitation letter may not suffice, and emphasize the need for additional documentation, such as business letters, particularly when engaging in soft power activities.