Chapter 48 makes a distinction between a true Sadguru and other types of gurus. What characteristics are mentioned that do *not* necessarily indicate a true Sadguru?

In Chapter 48, the author clarifies what does not make someone a Sadguru. It is stated that wise men do not confer the title of Sadguru simply upon those who have studied the Vedas, know the six Shastras, or explain Vedanta. Furthermore, practices like controlling breath (Pranayama), wearing heated marks (Taptamudra), or giving pleasing talks about Brahman without personal experience are insufficient. The text describes such knowledge as 'verbally hollow' if it lacks the 'taste of experience.' Giving mantras without any certainty of when the disciple will attain the fruit is another characteristic of a teacher who is not a true Sadguru.