The "doctype" part is case-insensitive, according to the pseudostandard on WhatWG.org: http://www.whatwg.org/specs/web-apps/current-work/multipage/... I guess your editor was configured incorrectly; shows up fine in both forms in Vim.
The "doctype" part is case-insensitive, according to the pseudostandard on WhatWG.org: http://www.whatwg.org/specs/web-apps/current-work/multipage/... I guess your editor was configured incorrectly; shows up fine in both forms in Vim.