बौधायन श्रौतसूत्रम् (कृष्ण यजुर्वेद तैत्तिरीय शाखा - सम्पूर्ण प्रश्न एवं श्रौत-याग कल्प सटीक)

..." ? No, that's not a valid letter.
Wait, let's look at:
"उपसादयत्य॑थाध्वर्यूरङ्गिरुदैति३"
Wait, why is there a cross/plus sign over 'रुदैति'?
Ah! There is a small mark before 'ऽथर्वान्क्रतू-':
Wait, look at:
"रुदैति३ ۠ ऽथर्वान्क्रतू-"
Wait, is that a cross? It looks like a dagger or an asterisk or footnote mark?
Wait, there are footnote numbers:
Footnote 1: १ in line 10.
Footnote 2: २ in line 11.
Footnote 3: ३ after रुदैति in line 14.
Wait, what is that symbol after ३?
It looks like a Maltese cross or a flower: ✠ or ⸭ or something? No, it's a raised mark, or is it footnote 4?
Wait! Where is footnote 4?
Look at footnote 4 at the bottom:
"४ Some of the MSS. insert ग्रहं ।"
Where is footnote 4 in the text?
Ah! Footnote 4 is in line 16:
"कर्माग्रयणाद्ग्रहार्दाग्रयणं४" - look, there is a small ४ after 'ग्रयणं'!
Then what is that mark after 'रुदैति३'?
Let's zoom in on line 14: