anchor.diff:     (versions :initarg :versions
   	     :initform (error "Provide a library version at least")
   	     :accessor library-versions
  -	     :documentation "The library versions"))
  +	     :documentation "The library versions")
  +   (tags :initarg :tags
  +	 :initform nil
  +	 :accessor library-tags
  +	 :documentation "Library tags"))
     (:documentation "A library meta description"))
   
   (defmethod print-object ((library cld-library) stream)
  
positive.code: 
  (defmacro deflibrary (name &body options)
    (destructuring-bind (&key author maintainer description
  			    license cld versions)
        options
      `(make-instance 'cld-library
  		    :name ',(if (symbolp name)
  
negative.code: 		    :description ,description
  		    :license ,license
  		    :cld ,cld
  		    :versions ,(parse-cld-library-versions versions)
  		    :tags ',tags)))
  
  (defun parse-cld-library-versions (versions)
    `(list
  