Would love if this could be fully investigated to ensure most recommended/friendliest defaults for the common case I'm targeting. I understand many subsets may be unnecessary(especially the things I'm not doing find/replace on inside of %'s) but I don't see PUT's for subsets, nor do I know if it will generate its own default values for me, anyway.

formattedSelfServePolicy.xml

<?xml version="1.0" encoding="UTF-8"?>
<policy>
  <general>
    <id>%PCY_ID%</id>
    <name>SelfServeLatest_%PROD_NAME%</name>
    <enabled>true</enabled>
    <trigger>USER_INITIATED</trigger>
    <trigger_checkin>false</trigger_checkin>
    <trigger_enrollment_complete>false</trigger_enrollment_complete>
    <trigger_login>false</trigger_login>
    <trigger_logout>false</trigger_logout>
    <trigger_network_state_changed>false</trigger_network_state_changed>
    <trigger_startup>false</trigger_startup>
    <trigger_other/>
    <frequency>Once per computer</frequency>
    <target_drive>default</target_drive>
    <offline>false</offline>
    <category>
      <id>-1</id>
      <name>Unknown</name>
    </category>
    <date_time_limitations>
      <activation_date/>
      <activation_date_epoch>0</activation_date_epoch>
      <activation_date_utc/>
      <expiration_date/>
      <expiration_date_epoch>0</expiration_date_epoch>
      <expiration_date_utc/>
      <no_execute_on/>
      <no_execute_start/>
      <no_execute_end/>
    </date_time_limitations>
    <network_limitations>
      <minimum_network_connection>No Minimum</minimum_network_connection>
      <any_ip_address>true</any_ip_address>
      <network_segments/>
    </network_limitations>
    <override_default_settings>
      <target_drive>default</target_drive>
      <distribution_point/>
      <force_afp_smb>false</force_afp_smb>
      <sus>default</sus>
      <netboot_server>current</netboot_server>
    </override_default_settings>
    <network_requirements>Any</network_requirements>
    <site>
      <id>-1</id>
      <name>None</name>
    </site>
  </general>
  <scope>
    <all_computers>false</all_computers>
    <computers/>
    <computer_groups>
      <computer_group>
        <id>%grp_id%</id>
        <name>lessThanMostRecent_%PROD_NAME%</name>
      </computer_group>
    </computer_groups>
    <buildings/>
    <departments/>
    <limit_to_users>
      <user_groups/>
    </limit_to_users>
    <limitations>
      <users/>
      <user_groups/>
      <network_segments/>
    </limitations>
    <exclusions>
      <computers/>
      <computer_groups/>
      <buildings/>
      <departments/>
      <users/>
      <user_groups/>
      <network_segments/>
    </exclusions>
  </scope>
  <self_service>
    <use_for_self_service>true</use_for_self_service>
    <install_button_text>Install</install_button_text>
    <self_service_description/>
    <force_users_to_view_description>false</force_users_to_view_description>
    <self_service_icon/>
  </self_service>
  <package_configuration>
    <packages>
      <size>1</size>
      <package>
        <id>1</id>
        <name>%PKG_NAME%</name>
        <action>Install</action>
        <fut>false</fut>
        <feu>false</feu>
        <update_autorun>false</update_autorun>
      </package>
    </packages>
  </package_configuration>
  <scripts>
    <size>0</size>
  </scripts>
  <printers>
    <size>0</size>
    <leave_existing_default/>
  </printers>
  <dock_items>
    <size>0</size>
  </dock_items>
  <account_maintenance>
    <accounts>
      <size>0</size>
    </accounts>
    <directory_bindings>
      <size>0</size>
    </directory_bindings>
    <management_account>
      <action>doNotChange</action>
    </management_account>
    <open_firmware_efi_password>
      <of_mode>none</of_mode>
      <of_password/>
    </open_firmware_efi_password>
  </account_maintenance>
  <reboot>
    <message>This computer will restart in 5 minutes. Please save anything you are working on and log out by choosing Log Out from the bottom of the Apple menu.</message>
    <startup_disk>Current Startup Disk</startup_disk>
    <specify_startup/>
    <no_user_logged_in>Restart if a package or update requires it</no_user_logged_in>
    <user_logged_in>Restart if a package or update requires it</user_logged_in>
    <minutes_until_reboot>5</minutes_until_reboot>
  </reboot>
  <maintenance>
    <recon>true</recon>
    <reset_name>false</reset_name>
    <install_all_cached_packages>false</install_all_cached_packages>
    <heal>false</heal>
    <prebindings>false</prebindings>
    <permissions>false</permissions>
    <byhost>false</byhost>
    <system_cache>false</system_cache>
    <user_cache>false</user_cache>
    <verify>false</verify>
  </maintenance>
  <files_processes>
    <search_by_path/>
    <delete_file>false</delete_file>
    <locate_file/>
    <update_locate_database>false</update_locate_database>
    <spotlight_search/>
    <search_for_process/>
    <kill_process>false</kill_process>
    <run_command/>
  </files_processes>
  <user_interaction>
    <message_start/>
    <allow_users_to_defer>false</allow_users_to_defer>
    <allow_deferral_until_utc/>
    <message_finish/>
  </user_interaction>
</policy>

I was just able to add a category to 9.12 using the following XML and CURL command, FWIW:

curl -k -v -u admin:jamf1234 https://10.1.22.141:8443/JSSResource/categories/id/0 -X POST -T ~/Desktop/category.xml

<?xml version="1.0" encoding="utf-8"?>
<category>
    <name>VLC</name>
</category>