Found the following validation problem for the NEWS.Rd HTML conversion:
NEWS.html:71:1 (inst/NEWS.Rd:31): Warning: <h4> anchor "Bug-fixes" already defined
NEWS.html:83:1 (inst/NEWS.Rd:37): Warning: <h4> anchor "User-visible-changes" already defined
NEWS.html:94:1 (inst/NEWS.Rd:42): Warning: <h4> anchor "Other-changes" already defined
NEWS.html:109:1 (inst/NEWS.Rd:50): Warning: <h4> anchor "Bug-fixes" already defined
NEWS.html:148:1 (inst/NEWS.Rd:74): Warning: <h4> anchor "Bug-fixes" already defined
NEWS.html:165:1 (inst/NEWS.Rd:84): Warning: <h4> anchor "User-visible-changes" already defined
NEWS.html:184:1 (inst/NEWS.Rd:95): Warning: <h4> anchor "Other-changes" already defined
NEWS.html:223:1 (inst/NEWS.Rd:120): Warning: <h4> anchor "Bug-fixes" already defined
NEWS.html:235:1 (inst/NEWS.Rd:126): Warning: <h4> anchor "User-visible-changes" already defined
NEWS.html:255:1 (inst/NEWS.Rd:138): Warning: <h4> anchor "New-features" already defined
NEWS.html:283:1 (inst/NEWS.Rd:157): Warning: <h4> anchor "Bug-fixes" already defined
NEWS.html:312:1 (inst/NEWS.Rd:177): Warning: <h4> anchor "User-visible-changes" already defined
NEWS.html:359:1 (inst/NEWS.Rd:210): Warning: <h4> anchor "Other-changes" already defined
NEWS.html:379:1 (inst/NEWS.Rd:222): Warning: <h4> anchor "Deprecated-and-defunct" already defined
NEWS.html:400:1 (inst/NEWS.Rd:235): Warning: <h4> anchor "Other-changes" already defined
NEWS.html:415:1 (inst/NEWS.Rd:243): Warning: <h4> anchor "Bug-fixes" already defined
NEWS.html:431:1 (inst/NEWS.Rd:252): Warning: <h4> anchor "New-features" already defined
NEWS.html:448:1 (inst/NEWS.Rd:262): Warning: <h4> anchor "Bug-fixes" already defined
NEWS.html:476:1 (inst/NEWS.Rd:280): Warning: <h4> anchor "User-visible-changes" already defined
NEWS.html:492:1 (inst/NEWS.Rd:289): Warning: <h4> anchor "Deprecated-and-defunct" already defined
NEWS.html:515:1 (inst/NEWS.Rd:303): Warning: <h4> anchor "Bug-fixes" already defined
NEWS.html:549:1 (inst/NEWS.Rd:327): Warning: <h4> anchor "User-visible-changes" already defined
NEWS.html:560:1 (inst/NEWS.Rd:332): Warning: <h4> anchor "Other-changes" already defined
NEWS.html:575:1 (inst/NEWS.Rd:340): Warning: <h4> anchor "Bug-fixes" already defined
NEWS.html:591:1 (inst/NEWS.Rd:349): Warning: <h4> anchor "User-visible-changes" already defined
NEWS.html:606:1 (inst/NEWS.Rd:357): Warning: <h4> anchor "Bug-fixes" already defined
NEWS.html:618:1 (inst/NEWS.Rd:363): Warning: <h4> anchor "User-visible-changes" already defined
NEWS.html:633:1 (inst/NEWS.Rd:371): Warning: <h4> anchor "New-features" already defined
NEWS.html:815:1 (inst/NEWS.Rd:512): Warning: <h4> anchor "Bug-fixes" already defined
NEWS.html:977:1 (inst/NEWS.Rd:636): Warning: <h4> anchor "User-visible-changes" already defined
NEWS.html:1102:1 (inst/NEWS.Rd:731): Warning: <h4> anchor "Other-changes" already defined
NEWS.html:1115:1 (inst/NEWS.Rd:738): Warning: <h4> anchor "Deprecated-and-defunct" already defined