111 Soledad St. San Antonio, TX 78205. Please fill out every box.We are honored to welcome them, and you, into the military family. ONCE YOU HAVE RECEIVED A CYBER PROPONENT PRE-DETERMINATION LETTER, YOU MUST SUBMIT AN ADDITIONAL REQUEST AND UPLOAD THE LETTER TO THIS WEBSITE. In order to file a DD 214, the County Clerk's Office requires proof of age and identity and the original, complete DD 214. This is your guide for their mailing address and letter ideas. Below is the address format for each basic training location to send your letter.