MilX Layers: how overlays are saved and loaded

Layers are how map.army keeps a tactical situation organised, and MilX is the format those layers are saved in. This page explains what a MilX layer is and how saving and loading work, then points you to the step-by-step pages for each task.

What a MilX layer is

A MilX layer holds the military symbols you draw for one part of a situation — typically grouped by phase, unit, or sector. MilX is an XML-based format built around MIL-STD-2525 symbology, so a saved layer keeps every symbol’s geometry and its editable attributes (affiliation, echelon, status, labels) — not just a flat picture.

When you save your work, map.army writes it to a file with the .milxlyz extension — the compressed MilX variant. A single layer is saved under the layer’s own name; several layers at once are bundled into one file called LayerCollection.milxlyz.

One thing a MilX file does not contain: imported vector and image layers. Those sit alongside your MilX layers in the app but are left behind when you save or share as MilX — see Import Overlays for how each layer type is handled.

Layers in an open session

While map.army is open, your layers live in the browser’s local cache for the site. There is no automatic “save and resume” — treat an open session like an unsaved document. A hard refresh or clearing site data loses unsaved MilX layers, and vector and image layers have to be re-added after any reload.

For the full breakdown of what survives a reload by layer type, see the session-persistence table in Edit Overlays.

Saving a layer

Saving exports your selected layers to a .milxlyz file in your download directory. Open the Layer Manager with the Map Overlays button, mark the layers you want, and use the save action; the file is named after the single layer, or LayerCollection.milxlyz when you save several.

A saved .milxlyz is your durable copy — it can be re-loaded later, moved to another machine, or sent to another map.army user. For the step-by-step, see Export Overlays.

Hint:

Save before any risky edit — a large delete, a layer merge, or switching work mode.

map.army

’s undo only recovers the last deleted symbol(s), so a recent .milxlyz is your real safety net.

Loading a layer

Loading a .milxlyz brings its layers back onto the map. Open the Layer Manager with the Map Overlays button and use the load action to pick the file.

The Local MilX Layers toolbar — the second icon loads a .milxlyz file

Imported layers are always added to whatever you already have open — existing layers are never overwritten or replaced, so you can combine several saved files into one situation. For the step-by-step, see Import Overlays.

The save-and-load cycle

Putting it together:

  1. Draw your symbols onto one or more layers — see Edit Overlays.
  2. Save to .milxlyz early and often, especially before risky edits.
  3. Load the file later — on the same machine or another — to keep working, with the layers added on top of the current map.

When you need a copy that lives server-side instead of on your device — for sharing, or as an extra backup — create a MilX Share instead of (or in addition to) saving locally; see How to create a share.