If you are using the latest (0.15.0) version of my TAK registration node then you can send a simple object to create the marker (values hardcoded just for demo)
msg.payload = {
name : "Caution-001",
lat: 52,
lon: -1,
icon:"6d781afb-89a6-4c07-b2b9-a89748b6a38f/Transport/caution.png",
SIDC: "SHGIIE",
remarks: "Oops - something to look out for here."
}
return msg;
Example flow
[{"id":"d49875594dc11c84","type":"tcp request","z":"f66c5e7c660b2aec","name":"","server":"takserver","port":"8087","out":"sit","ret":"string","splitc":" ","newline":"</event>","trim":true,"tls":"","x":670,"y":1040,"wires":[["e3a6624c9fc609b7"]]},{"id":"58d89fb93ad8e764","type":"tak registration","z":"f66c5e7c660b2aec","name":"House","callsign":"CJ","group":"Cyan","role":"Gateway","latitude":"51.05","longitude":"-1.35","repeat":"60","dphost":"","x":570,"y":980,"wires":[["d49875594dc11c84","a078df188bc96e57"]]},{"id":"e3a6624c9fc609b7","type":"debug","z":"f66c5e7c660b2aec","name":"debug 14","active":false,"tosidebar":true,"console":false,"tostatus":true,"complete":"true","targetType":"full","statusVal":"topic","statusType":"msg","x":860,"y":1040,"wires":[]},{"id":"327ef306fc571d89","type":"inject","z":"f66c5e7c660b2aec","name":"","props":[{"p":"payload"},{"p":"topic","vt":"str"}],"repeat":"","crontab":"","once":false,"onceDelay":0.1,"topic":"","payload":"","payloadType":"date","x":120,"y":940,"wires":[["15624f42e9a0cf31"]]},{"id":"15624f42e9a0cf31","type":"function","z":"f66c5e7c660b2aec","name":"function 6","func":"msg.payload = {\n name : \"Dave\",\n lat: 52,\n lon: -1,\n SIDC: \"SHGIIE\",\n remarks: \"Hey Dave\"\n}\nreturn msg;","outputs":1,"timeout":0,"noerr":0,"initialize":"","finalize":"","libs":[],"x":360,"y":940,"wires":[["58d89fb93ad8e764"]]},{"id":"a078df188bc96e57","type":"debug","z":"f66c5e7c660b2aec","name":"debug 17","active":true,"tosidebar":true,"console":false,"tostatus":true,"complete":"true","targetType":"full","statusVal":"topic","statusType":"msg","x":760,"y":980,"wires":[]},{"id":"6be38ff88df9b951","type":"inject","z":"f66c5e7c660b2aec","name":"","props":[{"p":"payload"},{"p":"topic","vt":"str"}],"repeat":"","crontab":"","once":false,"onceDelay":0.1,"topic":"","payload":"","payloadType":"date","x":120,"y":980,"wires":[["09c713fbc28e0501"]]},{"id":"09c713fbc28e0501","type":"function","z":"f66c5e7c660b2aec","name":"Caution","func":"msg.payload = {\n name : \"Caution-001\",\n lat: 52,\n lon: -1,\n icon:\"6d781afb-89a6-4c07-b2b9-a89748b6a38f/Transport/caution.png\",\n SIDC: \"SHGIIE\",\n remarks: \"Oops - something to look out for here.\"\n}\nreturn msg;","outputs":1,"timeout":0,"noerr":0,"initialize":"","finalize":"","libs":[],"x":360,"y":980,"wires":[["58d89fb93ad8e764"]]},{"id":"eab4981983d53f8b","type":"inject","z":"f66c5e7c660b2aec","name":"","props":[{"p":"payload"},{"p":"topic","vt":"str"}],"repeat":"","crontab":"","once":false,"onceDelay":0.1,"topic":"","payload":"","payloadType":"date","x":120,"y":1020,"wires":[["59f08089f0f4c561"]]},{"id":"59f08089f0f4c561","type":"function","z":"f66c5e7c660b2aec","name":"Awacs","func":"msg.payload = {\n name : \"AWACS\",\n lat: 51,\n lon: -2,\n icon:\"6d180afb-89a6-4c07-b2b3-a89748b6a38f/FalconView/E-3.png\",\n SIDC: \"SFGPU-------\",\n remarks: \"I'm watching you\"\n}\nreturn msg;","outputs":1,"timeout":0,"noerr":0,"initialize":"","finalize":"","libs":[],"x":350,"y":1020,"wires":[["58d89fb93ad8e764"]]},{"id":"4a017ece45e049ed","type":"inject","z":"f66c5e7c660b2aec","name":"","props":[{"p":"payload"},{"p":"topic","vt":"str"}],"repeat":"","crontab":"","once":false,"onceDelay":0.1,"topic":"","payload":"","payloadType":"date","x":120,"y":1060,"wires":[["4bced043c53463b2"]]},{"id":"4bced043c53463b2","type":"function","z":"f66c5e7c660b2aec","name":"Fema - Destroyed","func":"msg.payload = {\n name : \"A10\",\n lat: 51,\n lon: -3,\n icon:\"f8f7f666-8b28-4b57-9fbb-e48e61d33b79/Iron Sites/Structure Destroyed.png\",\n SIDC: \"SFGPU-------\",\n remarks: \"Bang\"\n}\nreturn msg;","outputs":1,"timeout":0,"noerr":0,"initialize":"","finalize":"","libs":[],"x":390,"y":1060,"wires":[["58d89fb93ad8e764"]]}]