Backloading Limits for 401(k) Match / Other DC

[HCbs]

Hello:

Can someone remind me what drives the the degree to which a DC plan can service-weight its contribution schedule? How about a 401(k) match that is tiered by service category? Ultimately, is it simply a 401(a)(4) / cross test issue that must be tested or is there a 411 restriction as well? Any safe harbors?

Thanks.

[PensionPro]

A match tiered by service is subject to BRF testing. I don't understand the comment about 411 restriction.