Weighted average coupon rate is at-issue or price-adjusted?

[Carsson3]

When a fund company quotes an end of period weighted average coupon rate for a bond fund, there is no explicit indication online whether the quote is (1) the weighted averge of the at-issue coupon rates of fund holdings, or alternatively (2) the weighted average price adjusted coupon rates of fund holdings.
Asking customer-facing financial company employees this question gets me nowhere in particular. Employees say they do not know, or they seem to guess, since it's easy to pick one alternative or the other based on something less than solid knowledge. Two very large fund companies have given me conflicting answers, which could indicate there is no governmental rule applicable for this context. It is shocking what basic bond concepts fund company employees do not understand at all, with presumably all their BBAs and MBAs (which I do not have).
So I am down to wondering what governmental rule might apply here either way, if there is one, and how to find online the official statement of any such rule. Or at least what agency would promulgate such a rule (if not everyone is already fired).
The usefulness of knowing the answer to this question may be for TIPS funds, where the weighted average price-adjusted coupon is also the buyer's real coupon.

[Beensabu]

Coupon rate is at-issue, I believe. The original "contract" rate that comes with the bond.

For price-adjusted, look at yield-to-maturity.

Edit: From VIPSX notes:

This figure is an estimated yield-to-maturity (YTM) for the fund. It is calculated by adding the trailing 12-month inflation adjustment to the "real" (i.e., before inflation) YTM of the fund. Adding the 12-month inflation adjustment allows the fund's yield to be more directly comparable to those of other bond funds. Investors should recognize that the actual YTM will depend upon the level of inflation experienced going forward.

[Geologist]

The phone representatives are there to answer questions about customer's accounts. At best, they have secondary knowledge of details about how funds work and how various elements of a fund are calculated. Further, few customers care about this. Thus I'm not surprised that you have had trouble with finding out information like this from more than one fund company.

(It could easily be that the only governmentally specified rate associated with bond funds is the SEC yield, which the SEC devised so that there would be a standard calculation for comparing funds as long as you have this value for the same day for each fund.)

[jeffyscott]

The usefulness of knowing the answer to this question may be for TIPS funds, where the weighted average price-adjusted coupon is also the buyer's real coupon.

I don't understand why you think that's useful information, but perhaps you could check what they are using by doing your own calculation. TIPS funds don't have that many holdings to review. Vanguard's short term TIPS fund VTAPX has only 26 holdings, for example.

Could you download or copy the VTAPX holdings from Vanguard to a spreadsheet and then calculate the weighted coupon both ways from that?

[coachd50]

When a fund company quotes an end of period weighted average coupon rate for a bond fund, there is no explicit indication online whether the quote is (1) the weighted averge of the at-issue coupon rates of fund holdings, or alternatively (2) the weighted average price adjusted coupon rates of fund holdings.
Asking customer-facing financial company employees this question gets me nowhere in particular. Employees say they do not know, or they seem to guess, since it's easy to pick one alternative or the other based on something less than solid knowledge. Two very large fund companies have given me conflicting answers, which could indicate there is no governmental rule applicable for this context. It is shocking what basic bond concepts fund company employees do not understand at all, with presumably all their BBAs and MBAs (which I do not have).
So I am down to wondering what governmental rule might apply here either way, if there is one, and how to find online the official statement of any such rule. Or at least what agency would promulgate such a rule (if not everyone is already fired).
The usefulness of knowing the answer to this question may be for TIPS funds, where the weighted average price-adjusted coupon is also the buyer's real coupon.

Edited - in looking up the terms here- I only see information about the weighted average coupon rate being used with mortgage backed securities.

I am unfamiliar with the metric- how is it generally used based on your experience? Which funds?