Found the following validation problem for the NEWS.Rd HTML conversion:
NEWS.html:43:1 (inst/NEWS.Rd:14): Warning: <h4> anchor "Bug-fixes" already defined
NEWS.html:61:1 (inst/NEWS.Rd:24): Warning: <h4> anchor "Bug-fixes" already defined
NEWS.html:76:1 (inst/NEWS.Rd:32): Warning: <h4> anchor "Bug-fixes" already defined
NEWS.html:94:1 (inst/NEWS.Rd:41): Warning: <h4> anchor "Bug-fixes" already defined
NEWS.html:109:1 (inst/NEWS.Rd:50): Warning: <h4> anchor "Bug-fixes" already defined
NEWS.html:127:1 (inst/NEWS.Rd:59): Warning: <h4> anchor "Bug-fixes" already defined
NEWS.html:172:1 (inst/NEWS.Rd:81): Warning: <h4> anchor "Bug-fixes" already defined
NEWS.html:193:1 (inst/NEWS.Rd:94): Warning: <h4> anchor "Bug-fixes" already defined
NEWS.html:209:1 (inst/NEWS.Rd:103): Warning: <h4> anchor "Bug-fixes" already defined
NEWS.html:233:1 (inst/NEWS.Rd:115): Warning: <h4> anchor "Miscellaneous" already defined
NEWS.html:248:1 (inst/NEWS.Rd:123): Warning: <h4> anchor "Bug-fixes" already defined
NEWS.html:264:1 (inst/NEWS.Rd:133): Warning: <h4> anchor "User-visible-changes" already defined
NEWS.html:296:1 (inst/NEWS.Rd:149): Warning: <h4> anchor "Bug-fixes" already defined
NEWS.html:323:1 (inst/NEWS.Rd:162): Warning: <h4> anchor "Miscellaneous" already defined
NEWS.html:345:1 (inst/NEWS.Rd:173): Warning: <h4> anchor "User-visible-changes" already defined
NEWS.html:358:1 (inst/NEWS.Rd:180): Warning: <h4> anchor "Miscellaneous" already defined
NEWS.html:383:1 (inst/NEWS.Rd:193): Warning: <h4> anchor "Bug-fixes" already defined
NEWS.html:399:1 (inst/NEWS.Rd:202): Warning: <h4> anchor "User-visible-changes" already defined
NEWS.html:441:1 (inst/NEWS.Rd:233): Warning: <h4> anchor "Miscellaneous" already defined
NEWS.html:473:1 (inst/NEWS.Rd:251): Warning: <h4> anchor "Bug-fixes" already defined
NEWS.html:509:1 (inst/NEWS.Rd:270): Warning: <h4> anchor "User-visible-changes" already defined
NEWS.html:548:1 (inst/NEWS.Rd:292): Warning: <h4> anchor "Miscellaneous" already defined
NEWS.html:579:1 (inst/NEWS.Rd:308): Warning: <h4> anchor "Bug-fixes" already defined
NEWS.html:612:1 (inst/NEWS.Rd:326): Warning: <h4> anchor "User-visible-changes" already defined
NEWS.html:640:1 (inst/NEWS.Rd:340): Warning: <h4> anchor "Miscellaneous" already defined
NEWS.html:678:1 (inst/NEWS.Rd:360): Warning: <h4> anchor "Bug-fixes" already defined
NEWS.html:706:1 (inst/NEWS.Rd:375): Warning: <h4> anchor "User-visible-changes" already defined
NEWS.html:749:1 (inst/NEWS.Rd:400): Warning: <h4> anchor "Miscellaneous" already defined
NEWS.html:777:1 (inst/NEWS.Rd:416): Warning: <h4> anchor "Bug-fixes" already defined
NEWS.html:816:1 (inst/NEWS.Rd:438): Warning: <h4> anchor "User-visible-changes" already defined
NEWS.html:829:1 (inst/NEWS.Rd:445): Warning: <h4> anchor "Miscellaneous" already defined
NEWS.html:840:1 (inst/NEWS.Rd:450): Warning: <h4> anchor "Bug-fixes" already defined
NEWS.html:864:1 (inst/NEWS.Rd:463): Warning: <h4> anchor "Miscellaneous" already defined
NEWS.html:892:1 (inst/NEWS.Rd:477): Warning: <h4> anchor "Bug-fixes" already defined
NEWS.html:915:1 (inst/NEWS.Rd:491): Warning: <h4> anchor "User-visible-changes" already defined
NEWS.html:941:1 (inst/NEWS.Rd:509): Warning: <h4> anchor "Miscellaneous" already defined
NEWS.html:964:1 (inst/NEWS.Rd:520): Warning: <h4> anchor "Bug-fixes" already defined
NEWS.html:986:1 (inst/NEWS.Rd:531): Warning: <h4> anchor "User-visible-changes" already defined
NEWS.html:1043:1 (inst/NEWS.Rd:560): Warning: <h4> anchor "Miscellaneous" already defined
NEWS.html:1069:1 (inst/NEWS.Rd:570): Warning: <h4> anchor "Bug-fixes" already defined
NEWS.html:1408:1 (inst/NEWS.Rd:742): Warning: <h4> anchor "Miscellaneous" already defined