IRS Code for In-Plan After-Tax to Roth Conversion

A participant would like to do an in-plan conversion of after-tax contributions to Roth. Which code would be used for this distribution?

Thanks.

From page 5 of 1099-R Instructions:

For a direct rollover of a distribution from a section 401(k) plan, a section 403(b) plan, or a governmental section 457(b) plan to a designated Roth account in the same plan, enter the amount rolled over in box 1, the taxable amount in box 2a, and any basis recovery amount in box 5. Use Code G in box 7.

I think this applies whether pre- or after-tax. Taxable amount in Box 2a would be only the accumulated earnings, if any, on the after-tax contributions.

I know this is an old post but I was wondering if this is still how other TPA firms are preparing the 1099-R for an in-plan conversion of after-tax to Roth. Instructions remain the same and that was my understanding. However, I've had other colleagues believe that it should be code 2 or 7 depending on age.