Cable retainer implementations of a cable retaining system for use with patch panels and other multiport communication equipment are discussed herein. The second display may be substantially transparent during an inactive state, and may overlay the first display. A positioning pin is mounted so as to be inserted through a through hole of a rear cover from the outside. The technique may further include designating an area as interesting if it includes a desired feature, and designating an area as non-interesting if it does not include the desired feature. In the production of a compound represented by the formula :The water content is adjusted to a level of from 5 to 15%, and the crystal form is controlled to be crystal form A, thereby to obtain a drug substance excellent in stability.