I switched over from prime v25.6 to v25.7.
Since I switched over I see an extra text at the result.txt.
With 25.6 I had results like:

[Fri Oct 10 20:25:04 2008]
21181*2^15854852+1 completed P-1, B1=130000, B2=2200000, Wd1: 9A15E8A8

And now with 25.7 I mostly get results like:

[Tue Oct 14 22:45:12 2008]
55459*2^16041334+1 completed P-1, B1=130000, B2=2200000, E=6, Wd1: 9F09E1E8

What does E=6 mean?