The MapCSS layer feature lets surimpose various colorized warning layers. The bottom layers are wider to be seen under other layers.

Bottom layer Z-index = -2
Fixme and Canvec Fixme Prefixes (Canada Canvec imports / OSM comparisions using Fixme Prefixes).

• dashed orange : Fixme attribue (ie. objects with a Fixme attribute.
• dashed orange-#CC0033 : Commited Fixme Prefix, – Canvec feature does not match any Osm feature. Missing/Misclassified Osm feature?
• dashed orange-green : Omited Fixme Prefix, – Osm feature does not match any Canvec feature. Missing/Misclassified Canvec feature?
• dashed orange-blue : Unmatched Fixme Prefix, – OSM and Canvec geometries are significantly different.Geometries need to be fixed?
• dashed orange-yellow : Attributed Fixme Prefix, – Osm and Canvec geometries matched but some common attributes differ. Attributes need to be fixed?

Middle layer Z-index = -1
Unnamed roads

• red : Unnamed roads (ie. Highway with no name attribute).

Top layer
Reserved for other styles such as Potlatch2 or Mapnik

• the highway layer appears over the Fixme and Unnamed layers.

meta 
{
    title: "FIXME";
    icon: "error_small.png";
    shortdescription: "FIXME Highlight Warnings";
    description: "This MapCSS style highlights ways/Polygons that contain Fixme attribute and unnamed highways. This style may be used alone or combined with other styles such as Potlatch2 and Mapnik (Tested in JOSM only).";
    version: "0.20_2017-10-30";
    author: "pierzen";
    min-josm-version: 7110;
}

/*
        The MapCSS layer feature lets surimpose various levels of warning layers. The bottom layers are wider to be seen under other layers.
        
                Bottom layer, dashed orange : Fixme attribue (ie. objects with a Fixme attribute.
                Fixme with Canvec Prefixes (Canada Canvec imports / OSM Comparison)
                dashed orange-#CC0033 : Commited – Canvec feature does not match any Osm feature. Missing/Misclassified Osm feature?
                dashed orange-green : Omited – Osm feature does not match any Canvec feature. Missing/Misclassified Canvec feature?
                dashed orange-blue : Unmatched – OSM and Canvec geometries are significantly different.Geometries need to be fixed?
                dashed orange-yellow : Attributed – Osm and Canvec geometries matched but some common attributes differ. Attributes need to be fixed?
                
                Middle layer, red   : Unnamed roads (ie. Highway with no name attribute).
                
                Top layer                       : Highway attribute (ie. Primary, Secondary, etc.) Potlatch2 style may be used over this Fixme Style. 
                
*/

canvas {
    fill-color: #ffffea;
    default-lines: false;
    default-points: false;
}

way[!highway] {
        color : gray;
        width:0.5;
}
node|z1-17 { symbol-shape: square; symbol-stroke-color: rosybrown; symbol-fill-color: rosybrown; symbol-size: 1; z-index:1}
node|z18 { symbol-shape: square; symbol-stroke-color: navy; symbol-fill-color: rosybrown; symbol-size:3;  z-index:1}
node|z19- { symbol-shape: square; symbol-stroke-color: navy; symbol-fill-color: rosybrown; symbol-size:5;  z-index:1}
area|z1-12:closed,way|z1-12[building]  { color: red; fill-color:red; opacity:1 width: 10;}

/* Fixme Layer, width=30 */

node["fixme"]

{
    width: 30; casing-width: +2;
    color: orange;
        z-index: -2;
}
way["fixme"]::way_fixme

{
    color: white; width:30; opacity:0.5; z-index: -2;
    dashes: 20,30;
    dashes-background-color: orange;
}

/* Canada Canvec-OSM comparison fixme messages ^= Prefix match */

node["fixme" ^= "Commited"], way["fixme" ^= "Commited"]::fixme
{
    color: #CC0033; width:30; opacity:0.5; z-index: -2;
    dashes: 20,30;
    dashes-background-color: orange;
}

node["fixme" ^= "Omited"], way["fixme" ^= "Omited"]::fixme
{
    color: green; width:30; opacity:0.5; z-index: -2;
    dashes: 20,30;
    dashes-background-color: orange;
}

node["fixme" ^= "Unmatched"], way["fixme" *= "Unmatched"]::fixme

{
    color: blue; width:30; opacity:0.5; z-index: -2;
    dashes: 20,30;
    dashes-background-color: orange;
}

node["fixme" ^= "Attributed"], way["fixme" ^= "Attributed"]::fixme
{
    color: yellow; width:30; opacity:0.5; z-index: -2;
    dashes: 20,30;
    dashes-background-color: orange;
}


/* UNNAMED HIGHWAYS (except noname=yes, junction=roundabout, service, track, path and pedestrian) RED Layer, width=20 */


way[highway=service]::way_except, way[highway=track]::way_except, way[highway=path]::way_except, way[highway=pedestrian]::way_except {
        width:0.5; color:gray;
    z-index: -2;  
}

way[highway][!name][noname!=yes][junction!=roundabout]::way_unnamed {
    color: red; width:20; opacity:0.4; z-index: -1;
}

/* removed way[highway=pedestrian][!name]::way_service, way[highway=service][!name]::way_service {
    color: #EAEEEA; width:20; z-index: 0;
} */

way[highway]::way_except {
    width:0.5;
    z-index: -1;  
}

way[highway][name]::way_named {
    width: 3;
    casing-width: 0;
    z-index: -1;  
}

Styles_Fixme-style.mapcss, Styles_Fixme.zip