Narada Purana (Jyotisha Selections) · by Vyasa
Chapter 8 · Marriage
विवाहः
सा कर्तरीति विज्ञेया दंपत्योर्गलकर्तरी ।कर्तरीयोगदुष्टं यल्लग्नं तत्परिवर्जयेत् ॥ ४५१ ॥
In the full Narada Purana (Purva Bhaga) this is chapter 56, verse 451.
that is known as kartari (scissors fault), the throat-scissors of the couple. A lagna (rising sign) spoiled by the kartari should be dropped.
Simple meaning: Bad planets on both sides of the lagna cut it. Do not use such a lagna.
अपि सौम्यग्रहैर्युक्तं गुणैः सर्वैः समन्वितम् ।
The Moon in the 6th, 8th or 12th spoils a lagna even when it looks good.
तल्लग्नं वर्जयेद्यत्नाज्जीवशुक्रसमन्वितम् ।
Drop such a lagna even with Jupiter and Venus, and whatever the Moon's sign.
अपि सर्वगुणोपेतं दंपत्योर्निधनप्रदम् ।
It may put the couple's life at risk. The Moon joined by any planet is the Samgraha fault.