Text Screens?!

I'm creating a new Doom 2 wad and I need some help, how do I post text screens?
(If you don't know what text screens are, check this out http://doomwiki.org/wiki/Text_screen)

I know this is possible because I've seen Doom wads with these screens, but it seems like there are no tutorials on the internet about this, any help?

r_init: getpostnumberforname: post not found!

If it's ZDoom: http://zdoom.org/wiki/MAPINFO/Cluster_definition

If you want compatibility with vanilla / Boom / classic non-ZDoom ports, you shouldn't use MAPINFO (less-advanced ports don't support it), but you can still make a DEHACKED patch to modify the intermission text strings after MAP06, 11, 31, 32, 20 and 30. However, DEHACKED doesn't allow you to change the mapslots after which the texts appear. To make and edit DEHACKED patches, use WhackEd editor.

scifista42 said:

However, DEHACKED doesn't allow you to change the mapslots after which the texts appear.

And the text string length itself is severely limited.

Linguica said:

If it's ZDoom: http://zdoom.org/wiki/MAPINFO/Cluster_definition

I'm confused, do I post it in the script editor or the mapinfo file? Because all this is in my MAPINFO file:

"scriptlang "MapInfo"
{
	lumpname		{ MAPINFO D1INFO D2INFO PLUTINFO TNTINFO HERINFO HEXNINFO STRFINFO }
	case_sensitive	0
}

keywords
{
	episode clearepisodes map clusterdef
	defaultmap levelnum next secretnext cluster doublesky sky1 sky2 fade outsidefog titlepatch
	par music cdtrack cdid nointermission exitpic enterpic intermusic nosoundclipping lookup
	allowmonstertelefrags specialaction map07special baronspecial cyberdemonspecial
	spidermastermindspecial specialaction_exitlevel specialaction_opendoor specialaction_lowerfloor
	specialaction_killmonsters lightning fadetable evenlighting vertwallshade horizwallshade
	forcenoskystretch noautosequences strictmonsteractivation laxmonsteractivation fallingdamage
	oldfallingdamage forcefallingdamage nofallingdamage gravity aircontrol airsupply filterstarts
	noinventorybar keepfullinventory entertext exittext music flat hub pic exittextislump noallies
	sucktime deathslideshow redirect strifefallingdamage ironlichspecial minotaurspecial dsparilspecial
}

constants
{
}

functions
{
}

Haha, I don't know why you went on looking for that, but what you're got here is an editor's syntax highlighting rules for ZDoom MAPINFO lumps, and not actually a MAPINFO lump.

Here's an example from Valiant:

In the MAPINFO lump:

clusterdef 1{
	exittextislump
	exittext = "E1TEXT"
	music = "D_READ_M"
	pic = "e1pic"
}

map MAP01 "Bad Reception"{
	titlepatch = "CWILV00"
	next = "MAP02"
	music = "D_RUNNIN"
	par = 230
	cluster = 1
	}

THE MANCUBIAN CANDIDATE CRUMPLES AND DIES,
SPILLING HIS SECRETS NEXT TO HIS INNARDS.
HIS GENETIC SEQUENCE HAS RUN FURTHER AMOK
THAN PROJECT VALIANT ITSELF, REWIRED AND
REWRITTEN MORE TIMES THAN A FAILED WRITER'S
MOST PRETENTIOUS MANUSCRIPT.  

VALIANT HAS TO BE STOPPED, NOW, BEFORE IT 
PROPAGATES THROUGHOUT THE UNIVERSE.

ONLY YOU STAND IN THE WAY OF A BIOENGINEERED, 
CYBERNETIC APOCALYPSE.

Gez said:

Haha, I don't know why you went on looking for that, but what you're got here is an editor's syntax highlighting rules for ZDoom MAPINFO lumps, and not actually a MAPINFO lump.

What do you suggest I do, then?

Open your wad in SLADE3 (wad content editor). Create an empty lump named "MAPINFO". Open the lump in text mode. Write your MAPINFO script there.