The <B> and <K> block markers aren't shown as they cause problems. If you use ^KH it will show these markers as thick vertical bars and the existace of these markers will be indicated in the Word Status Bar below your document.

If you want these thick vertical bars displayed by default each time you start Word, click Utilities then Options. Then in Word Options click the View tab, and then select the Bookmarks option and then click OK. (In the standard Word menus this is under Tools, Options).