#data
<!DOCTYPE html>Hello
#errors
#document
| <!DOCTYPE html>
| <html>
|   <head>
|   <body>
|     "Hello"

#data
<!dOctYpE HtMl>Hello
#errors
#document
| <!DOCTYPE html>
| <html>
|   <head>
|   <body>
|     "Hello"

#data
<!DOCTYPEhtml>Hello
#errors
#document
| <!DOCTYPE html>
| <html>
|   <head>
|   <body>
|     "Hello"

#data
<!DOCTYPE>Hello
#errors
#document
| <!DOCTYPE >
| <html>
|   <head>
|   <body>
|     "Hello"

#data
<!DOCTYPE >Hello
#errors
#document
| <!DOCTYPE >
| <html>
|   <head>
|   <body>
|     "Hello"

#data
<!DOCTYPE potato>Hello
#errors
#document
| <!DOCTYPE potato>
| <html>
|   <head>
|   <body>
|     "Hello"

#data
<!DOCTYPE potato >Hello
#errors
#document
| <!DOCTYPE potato>
| <html>
|   <head>
|   <body>
|     "Hello"

#data
<!DOCTYPE potato taco>Hello
#errors
#document
| <!DOCTYPE potato>
| <html>
|   <head>
|   <body>
|     "Hello"

#data
<!DOCTYPE potato taco "ddd>Hello
#errors
#document
| <!DOCTYPE potato>
| <html>
|   <head>
|   <body>
|     "Hello"

#data
<!DOCTYPE potato sYstEM>Hello
#errors
#document
| <!DOCTYPE potato>
| <html>
|   <head>
|   <body>
|     "Hello"

#data
<!DOCTYPE potato sYstEM    >Hello
#errors
#document
| <!DOCTYPE potato>
| <html>
|   <head>
|   <body>
|     "Hello"

#data
<!DOCTYPE   potato       sYstEM  ggg>Hello
#errors
#document
| <!DOCTYPE potato>
| <html>
|   <head>
|   <body>
|     "Hello"

#data
<!DOCTYPE potato SYSTEM taco  >Hello
#errors
#document
| <!DOCTYPE potato>
| <html>
|   <head>
|   <body>
|     "Hello"

#data
<!DOCTYPE potato SYSTEM 'taco"'>Hello
#errors
#document
| <!DOCTYPE potato>
| <html>
|   <head>
|   <body>
|     "Hello"

#data
<!DOCTYPE potato SYSTEM "taco">Hello
#errors
#document
| <!DOCTYPE potato>
| <html>
|   <head>
|   <body>
|     "Hello"

#data
<!DOCTYPE potato SYSTEM "tai'co">Hello
#errors
#document
| <!DOCTYPE potato>
| <html>
|   <head>
|   <body>
|     "Hello"

#data
<!DOCTYPE potato SYSTEMtaco "ddd">Hello
#errors
#document
| <!DOCTYPE potato>
| <html>
|   <head>
|   <body>
|     "Hello"

#data
<!DOCTYPE potato grass SYSTEM taco>Hello
#errors
#document
| <!DOCTYPE potato>
| <html>
|   <head>
|   <body>
|     "Hello"

#data
<!DOCTYPE potato pUbLIc>Hello
#errors
#document
| <!DOCTYPE potato>
| <html>
|   <head>
|   <body>
|     "Hello"

#data
<!DOCTYPE potato pUbLIc >Hello
#errors
#document
| <!DOCTYPE potato>
| <html>
|   <head>
|   <body>
|     "Hello"

#data
<!DOCTYPE potato pUbLIcgoof>Hello
#errors
#document
| <!DOCTYPE potato>
| <html>
|   <head>
|   <body>
|     "Hello"

#data
<!DOCTYPE potato PUBLIC goof>Hello
#errors
#document
| <!DOCTYPE potato>
| <html>
|   <head>
|   <body>
|     "Hello"

#data
<!DOCTYPE potato PUBLIC "go'of">Hello
#errors
#document
| <!DOCTYPE potato>
| <html>
|   <head>
|   <body>
|     "Hello"

#data
<!DOCTYPE potato PUBLIC 'go'of'>Hello
#errors
#document
| <!DOCTYPE potato>
| <html>
|   <head>
|   <body>
|     "Hello"

#data
<!DOCTYPE potato PUBLIC 'go:hh   of' >Hello
#errors
#document
| <!DOCTYPE potato>
| <html>
|   <head>
|   <body>
|     "Hello"

#data
<!DOCTYPE potato PUBLIC "W3C-//dfdf" SYSTEM ggg>Hello
#errors
#document
| <!DOCTYPE potato>
| <html>
|   <head>
|   <body>
|     "Hello"

#data
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN"
   "http://www.w3.org/TR/html4/strict.dtd">Hello
#errors
#document
| <!DOCTYPE html>
| <html>
|   <head>
|   <body>
|     "Hello"

#data
<!DOCTYPE ...>Hello
#errors
#document
| <!DOCTYPE ...>
| <html>
|   <head>
|   <body>
|     "Hello"

#data
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
#errors
#document
| <!DOCTYPE html>
| <html>
|   <head>
|   <body>

#data
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Frameset//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-frameset.dtd">
#errors
#document
| <!DOCTYPE html>
| <html>
|   <head>
|   <body>

#data
<!DOCTYPE root-element [SYSTEM OR PUBLIC FPI] "uri" [ 
<!-- internal declarations -->
]>
#errors
#document
| <!DOCTYPE root-element>
| <html>
|   <head>
|   <body>
|     "
]>"

#data
<!DOCTYPE html PUBLIC
  "-//WAPFORUM//DTD XHTML Mobile 1.0//EN"
    "http://www.wapforum.org/DTD/xhtml-mobile10.dtd">
#errors
#document
| <!DOCTYPE html>
| <html>
|   <head>
|   <body>

#data
<!DOCTYPE HTML SYSTEM "http://www.w3.org/DTD/HTML4-strict.dtd"><body><b>Mine!</b></body>
#errors
#document
| <!DOCTYPE html>
| <html>
|   <head>
|   <body>
|     <b>
|       "Mine!"