lib/less/parser/parser.js
function () {
                    var key, value;
                    parserInput.save();
                    key = parserInput.$re(/^\w+(?=\s?=)/i);
                    if (!key) {
                        parserInput.restore();
                        return;
                    }
                    if (!parserInput.$char('=')) {
                        parserInput.restore();
                        return;
                    }
                    value = parsers.entity();
                    if (value) {
                        parserInput.forget();
                        return new(tree.Assignment)(key, value);
                    } else {
                        parserInput.restore();
                    }
                }
function () {
                    var key, value;
                    parserInput.save();
                    key = parserInput.$re(/^\w+(?=\s?=)/i);
                    if (!key) {
                        parserInput.restore();
                        return;
                    }
                    if (!parserInput.$char('=')) {
                        parserInput.restore();
                        return;
                    }
                    value = parsers.entity();
                    if (value) {
                        parserInput.forget();
                        return new(tree.Assignment)(key, value);
                    } else {
                        parserInput.restore();
                    }
                }
function ( ) { var key , value ; parserInput . save ( ) ; key = parserInput . $re ( / ^\w+(?=\s?=) / i ) ; if ( ! key ) { parserInput . restore ( ) ; return ; } if ( ! parserInput . $char ( '=' ) ) { parserInput . restore ( ) ; return ; } value = parsers . entity ( ) ; if ( value ) { parserInput . forget ( ) ; return new ( tree . Assignment ) ( key , value ) ; } else { parserInput . restore ( ) ; } }
Assignments are argument entities for calls. They are present in ie filter properties as shown below.  filter: progid:DXImageTransform.Microsoft.Alpha( *opacity=50* )
Assignments are argument entities for calls . They are present in ie filter properties as shown below . filter : progid : DXImageTransform . Microsoft . Alpha ( * opacity = 50 * )