config.allowedContent = {
        sub: {
            classes: ['*']
        },
        sup: {
            classes: ['*'],
            attributes: ['data-id']
        },
        table: {
            attributes: ['*'],
            styles: ['*']
        },
        tr: {
            attributes: ['*'],
            styles: ['*']
        },
        th: {
            attributes: ['*'],
            classes: ['p-indent'],
            styles: ['*']
        },
        td: {
            attributes: ['*'],
            classes: ['p-indent'],
            styles: ['*']
        },
        tbody: {
            attributes: ['*'],
            styles: ['*']
        },
        thead: {
            attributes: ['*'],
            styles: ['*']
        },
        caption : {},
        img : {
            attributes: ['*'],
            classes: ['*'],
            styles: ['*']
        },
        code : {
            attributes: ['*'],
            classes: ['*'],
            styles: ['*']
        },
		pre : {
            attributes: ['*'],
            classes: ['*'],
            styles: ['*']
		},
        p : {
            styles: ['text-align',
                    'text-indent',
                    'border',
                    'border-bottom',
                    'border-top',
                    'border-left',
                    'border-right',
                    'background-color',
                    'margin',
                    'margin-top',
                    'margin-left',
                    'margin-right',
                    'margin-bottom'],
            classes: ['*']
        },
        strong : {},
        i : {},
        s : {},
        u : {},
        ul : {
            styles: ['list-style-type']
        },
        ol : {
            styles: ['list-style-type']
        },
        li : {
            styles: ['text-align', 'list-style-type']
        },
        blockquote : {},
        span : {
            attributes: ['*'],
            classes: ['*'],
            styles: ['*']
        },
        a : {
            attributes: ['href', 'data-anchor-id', 'data-chapter-id', 'placeholder'],
            classes: ['link-to-anchor'],
        },
        iframe : {
            attributes: ['*'],
            classes: ['*'],
            styles: ['*']
        },
        div : {
            attributes: ['*'],
            classes: ['youtube-embed-wrapper'],
            styles: ['*']
        },
        'h1 h2 h3 h4 h5 h6 h7 h8 h9': {
            styles: ['text-align',
                    'text-indent',
                    'border',
                    'border-bottom',
                    'border-top',
                    'border-left',
                    'border-right',
                    'background-color',
                    'margin',
                    'margin-top',
                    'margin-left',
                    'margin-right',
                    'margin-bottom'],
        },
        hr: {
            styles: ['border',
                    'border-bottom',
                    'border-top',
                    'border-left',
                    'border-right',
                    'margin',
                    'margin-top',
                    'margin-left',
                    'margin-right',
                    'margin-bottom'],
        }
    };