Question about bond fund yields

[disneysteve]

If you look at VUSFX on Vanguard's site, they list a 30-day SEC Yield of 0.38%.
If you look at Morningstar, they list a TTM Yield of 0.92%.
If you look at Google Finance, they list a Yield of 1.00%.

I realize they're all looking at yield in a different way but it's quite confusing when you're deciding whether or not to invest in a fund. There's a big difference between 0.38% and 1.0%. From the bit of reading I've done, it seems that the 30-day SEC Yield is the one to go with as that most accurately reflects the current yield as opposed to the historical yield (TTM is trailing 12 months). Am I correct on that?

[kork13]

I could try to summarize the difference, but this site explains it pretty well & I'll just point you there.

But the short story is that yes, the 30-day yield is what you should pay attention to when it comes to what you can expect to earn from it in the near term.