Hi @elisa.ervin ,
My appologies for the slow response, I was travelling for a site visit most of the week.
If you look at the abbreviations you see that ‘L’ accounts for not just the roof live load but also the floor live load. Since you are looking at deflection limits for a floor you will use the ‘L’ value. Because you are looking at a beam on an intermediate level, you will look at the row labled “Floor Members”.
The second column is concerned with snow and wind load. If you had been looking at vertical construction like exterior walls you would need to confirm you met the deflection limits for wind loads. If you were looking at roof systems you would need to confirm you met the deflection limits for snow loads. However, since we are looking at a floor member, we don’t need to worry about this deflection. That’s why there is no value in that cell.
The last column refers to the ‘creep’ that occurs after the construction has been in place. I’m thinking perhaps there was information in the question which would have steered you away from needing to use this column.
I found this article which also talks about this last column which shows deflection limits for D+L. Truss Deflection Changes You Should Know About | SBC Magazine
Hope this helps! I’m going to keep looking around to see if I can find a video on this as well. If I do I’ll post it here!