True vaishnava

What are the marks of a true Vaishnava?

In the Kapila Upapurana 21st chapter, there is a short discourse on Jnana Yoga. Nandikeshwara asks Mahaveda 'What are the marks 'signs' of a Vaishnava, the branding of the image of Shankha, Chakra, etc. on the body?'

Mahadeva replies:

Giving up desire and anger, those with a loin cloth, with sweet words, always their heart filled with ananda - these are the marks of a Vaishnava.

Singing the glories of Govinda shedding tears of joy, endowed with compassion, truth, free of the idea of 'I' and 'mine', worshiping the gods, brahmanas and making noble persons happy - these noble traits are the marks of a vaishnava.  

Others, without these traits, but with just the external marks of Shankha, Chakra, etc. are only vainglorious, making a show of the marks.  

From this we come to know that the physical marks of the conch, etc. is only secondary; unessential. The true Vaishnava traits are following and internalizing the ones enumerated above. Whether one is a bhasma dhaari or without any external marks, but possesses these noble traits, he is the true Vaishnava in the primary sense. In this very chapter the Hari Hara abheda is brought out in several ways along with the censure of perception of difference between the Two. Also, since the context is about the knowledge needed for Mukti, the traits listed here are the means to attain such knowledge. Someone without these qualities, even though dons the external marks, does not qualify to be a true Bhagavata. Only those who indulge in critiquing and insulting others actually destroy the Bhagavata Dharmas.    

मूर्खो वदति विष्णाय विद्वान् वदति विष्णवे। 

उभयोः सदृशं पुण्यं भावग्राही जनार्दनः ||

An unlettered one says 'Vishnaaya' while a learned man says 'Vishnave'. Both of them get the same punya since the Lord Janardana is pleased only with the true devotion.

We are reminded of the famous song 'Vaishnava Janato..'. https://allpoetry.com/Vaishnava-janatho-(With-English-Translation)

अहिंसा प्रथमं पुष्पं पुष्पमिन्द्रियनिग्रहः

सर्वभूतदयापुष्पं क्षमापुष्पं विशेषतः ।

ज्ञानपुष्पं तपःपुष्पं शान्तिपुष्पं तथैव च

सत्यमष्टविधं पुष्पं विष्णोः प्रीतिकरं भवेत् ॥

Read here the verses of the Kapila Upa purana: page 83 in this link https://vedicreserve.miu.edu/upapurana/kapila_purana.pdf