Markup language

All pages are conformity with the Recommendation of World Wide Web Consortium (W3C®), and described in the international standard markup language.

HTML5 Powered

The pages with above mark are conformity with W3C® XHTML 5.2.

* The standard XHTML 5.2 was withdrawn on January 28, 2021. However, it is compatible with the newest standard XML syntax for HTML Living Standard.

* Extension .html and MIME Type text/html are used for all the web page files, so as to be used by the old browsers that cannot use XHTML. Thus, the error returns because of XML declaration <?xml version="1.0" encoding="UTF-8"?> when the W3C® Markup Validation Service checks these pages. However, it is not defect. If you would like to validate the grammar of the web page, please excute the validation by uploading the source file of XHTML with changing the extention as .xhtml. In this case, no error will occur.