openlayers 2 - Hiding specific icons/markers on text generated vector layer

I'm displaying a vector layer with pois, generated from a text file:

lat lon icon    iconSize    iconOffset  title   description
56.030325   14.4774116666667    http://www.medinsbiologi.se/hano/Foto.png       -10.5,-25   102_1   UV-foto

Code to draw layer:

        var pois = new OpenLayers.Layer.Vector("Provpunkter", 
        {
        projection: map.displayProjection,
        strategies: [new OpenLayers.Strategy.Fixed()],
        protocol:   new OpenLayers.Protocol.HTTP(
            {
            url:        "../poi/DynPOIHano.txt",
            format:     new OpenLayers.Format.Text(

                {
                extractStyles: true,
                extractAttributes: true
                })
            })
        });

The layer shows up fine, and I have added descriptions to each poi. Now I'd like to be able to hide some of these markers depending on icon type, with a button somewhere else on the page. I've tried using features.style:

function hideFeatures() {
    var features = pois.features;

    for( var i = 0; i < features.length; i++ ) {
    features.style.display = 'none';
    }
    pois.redraw();
    }

but I don't seem to be able to identify the layers icons. Are they considered features, icons or markers? I know this can be done with the built-in OpenLayers.Control.LayerSwitcher() and by adding multiple layers, but would like to avoid that approach.

Answer

Ok, it seems the "icon" in my text file was not interpreted as an attribute at all, but as an externalGraphics link. Logical off course, I just didn't get it. So now I'm able to access my icons with:

function hideFeatures() {

var feature = pois.features;
        for( var i = 0; i < feature.length; i++ ) {
            if (feature[i].style.externalGraphic == "http://www.medinsbiologi.se/hano/ikon/Foto.png") {
            feature[i].style= { display: 'none' };
            }
        }
        pois.redraw();
        }    

Piece of cake... ;)