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Showing content from https://www.rfc-editor.org/rfc/rfc1521.ps below:

%!PS-Adobe-1.0 %%Creator: guppylake.bellcore.com:nsb (Nathaniel Borenstein) %%Title: stdin (ditroff) %%CreationDate: Tue Nov 30 07:43:41 1993 %%EndComments % lib/psdit.pro -- prolog for psdit (ditroff) files % Copyright (c) 1984, 1985 Adobe Systems Incorporated. All Rights Reserved. % last edit: shore Sat Nov 23 20:28:03 1985 % RCSID: %Header: psdit.pro,v 2.1 85/11/24 12:19:43 shore Rel % % Psfig RCSID $Header: psdit.pro,v 1.5 88/01/04 17:48:22 trevor Exp $ /$DITroff 180 dict def $DITroff begin /DocumentInitState [ matrix currentmatrix currentlinewidth currentlinecap currentlinejoin currentdash currentgray currentmiterlimit ] cvx def %% Psfig additions /startFig { /SavedState save def userdict maxlength dict begin currentpoint transform DocumentInitState setmiterlimit setgray setdash setlinejoin setlinecap setlinewidth setmatrix itransform moveto /ury exch def /urx exch def /lly exch def /llx exch def /y exch 72 mul resolution div def /x exch 72 mul resolution div def currentpoint /cy exch def /cx exch def /sx x urx llx sub div def % scaling for x /sy y ury lly sub div def % scaling for y sx sy scale % scale by (sx,sy) cx sx div llx sub cy sy div ury sub translate /DefFigCTM matrix currentmatrix def /initmatrix { DefFigCTM setmatrix } def /defaultmatrix { DefFigCTM exch copy } def /initgraphics { DocumentInitState setmiterlimit setgray setdash setlinejoin setlinecap setlinewidth setmatrix DefFigCTM setmatrix } def /showpage { initgraphics } def } def % Args are llx lly urx ury (in figure coordinates) /clipFig { currentpoint 6 2 roll newpath 4 copy 4 2 roll moveto 6 -1 roll exch lineto exch lineto exch lineto closepath clip newpath moveto } def % doclip, if called, will always be just after a `startfig' /doclip { llx lly urx ury clipFig } def /endFig { end SavedState restore } def /globalstart { % Push details about the enviornment on the stack. fontnum fontsize fontslant fontheight % firstpage mh my resolution slotno currentpoint pagesave restore gsave } def /globalend { grestore moveto /slotno exch def /resolution exch def /my exch def /mh exch def % /firstpage exch def /fontheight exch def /fontslant exch def /fontsize exch def /fontnum exch def F /pagesave save def } def %% end XMOD additions /fontnum 1 def /fontsize 10 def /fontheight 10 def /fontslant 0 def /xi {0 72 11 mul translate 72 resolution div dup neg scale 0 0 moveto /fontnum 1 def /fontsize 10 def /fontheight 10 def /fontslant 0 def F /pagesave save def}def /PB{save /psv exch def currentpoint translate resolution 72 div dup neg scale 0 0 moveto}def /PE{psv restore}def /arctoobig 90 def /arctoosmall .05 def /m1 matrix def /m2 matrix def /m3 matrix def /oldmat matrix def /tan{dup sin exch cos div}def /point{resolution 72 div mul}def /dround {transform round exch round exch itransform}def /xT{/devname exch def}def /xr{/mh exch def /my exch def /resolution exch def}def /xp{}def /xs{docsave restore end}def /xt{}def /xf{/fontname exch def /slotno exch def fontnames slotno get fontname eq not {fonts slotno fontname findfont put fontnames slotno fontname put}if}def /xH{/fontheight exch def F}def /xS{/fontslant exch def F}def /s{/fontsize exch def /fontheight fontsize def F}def /f{/fontnum exch def F}def /F{fontheight 0 le {/fontheight fontsize def}if fonts fontnum get fontsize point 0 0 fontheight point neg 0 0 m1 astore fontslant 0 ne{1 0 fontslant tan 1 0 0 m2 astore m3 concatmatrix}if makefont setfont .04 fontsize point mul 0 dround pop setlinewidth}def /X{exch currentpoint exch pop moveto show}def /N{3 1 roll moveto show}def /Y{exch currentpoint pop exch moveto show}def /S{show}def /ditpush{}def/ditpop{}def /AX{3 -1 roll currentpoint exch pop moveto 0 exch ashow}def /AN{4 2 roll moveto 0 exch ashow}def /AY{3 -1 roll currentpoint pop exch moveto 0 exch ashow}def /AS{0 exch ashow}def /MX{currentpoint exch pop moveto}def /MY{currentpoint pop exch moveto}def /MXY{moveto}def /cb{pop}def % action on unknown char -- nothing for now /n{}def/w{}def /p{pop showpage pagesave restore /pagesave save def}def /abspoint{currentpoint exch pop add exch currentpoint pop add exch}def /distance{dup mul exch dup mul add sqrt}def /dstroke{currentpoint stroke moveto}def /Dl{2 copy gsave rlineto stroke grestore rmoveto}def /arcellipse{/diamv exch def /diamh exch def oldmat currentmatrix pop currentpoint translate 1 diamv diamh div scale /rad diamh 2 div def currentpoint exch rad add exch rad -180 180 arc oldmat setmatrix}def /Dc{dup arcellipse dstroke}def /De{arcellipse dstroke}def /Da{/endv exch def /endh exch def /centerv exch def /centerh exch def /cradius centerv centerv mul centerh centerh mul add sqrt def /eradius endv endv mul endh endh mul add sqrt def /endang endv endh atan def /startang centerv neg centerh neg atan def /sweep startang endang sub dup 0 lt{360 add}if def sweep arctoobig gt {/midang startang sweep 2 div sub def /midrad cradius eradius add 2 div def /midh midang cos midrad mul def /midv midang sin midrad mul def midh neg midv neg endh endv centerh centerv midh midv Da currentpoint moveto Da} {sweep arctoosmall ge {/controldelt 1 sweep 2 div cos sub 3 sweep 2 div sin mul div 4 mul def centerv neg controldelt mul centerh controldelt mul endv neg controldelt mul centerh add endh add endh controldelt mul centerv add endv add centerh endh add centerv endv add rcurveto dstroke} {centerh endh add centerv endv add rlineto dstroke}ifelse}ifelse}def /Barray 200 array def % 200 values in a wiggle /D~{mark}def /D~~{counttomark Barray exch 0 exch getinterval astore /Bcontrol exch def pop /Blen Bcontrol length def Blen 4 ge Blen 2 mod 0 eq and {Bcontrol 0 get Bcontrol 1 get abspoint /Ycont exch def /Xcont exch def Bcontrol 0 2 copy get 2 mul put Bcontrol 1 2 copy get 2 mul put Bcontrol Blen 2 sub 2 copy get 2 mul put Bcontrol Blen 1 sub 2 copy get 2 mul put /Ybi /Xbi currentpoint 3 1 roll def def 0 2 Blen 4 sub {/i exch def Bcontrol i get 3 div Bcontrol i 1 add get 3 div Bcontrol i get 3 mul Bcontrol i 2 add get add 6 div Bcontrol i 1 add get 3 mul Bcontrol i 3 add get add 6 div /Xbi Xcont Bcontrol i 2 add get 2 div add def /Ybi Ycont Bcontrol i 3 add get 2 div add def /Xcont Xcont Bcontrol i 2 add get add def /Ycont Ycont Bcontrol i 3 add get add def Xbi currentpoint pop sub Ybi currentpoint exch pop sub rcurveto }for dstroke}if}def end /ditstart{$DITroff begin /nfonts 60 def % NFONTS makedev/ditroff dependent! /fonts[nfonts{0}repeat]def /fontnames[nfonts{()}repeat]def /docsave save def }def % character outcalls /oc {/pswid exch def /cc exch def /name exch def /ditwid pswid fontsize mul resolution mul 72000 div def /ditsiz fontsize resolution mul 72 div def ocprocs name known{ocprocs name get exec}{name cb} ifelse}def /fractm [.65 0 0 .6 0 0] def /fraction {/fden exch def /fnum exch def gsave /cf currentfont def cf fractm makefont setfont 0 .3 dm 2 copy neg rmoveto fnum show rmoveto currentfont cf setfont(\244)show setfont fden show grestore ditwid 0 rmoveto} def /oce {grestore ditwid 0 rmoveto}def /dm {ditsiz mul}def /ocprocs 50 dict def ocprocs begin (14){(1)(4)fraction}def (12){(1)(2)fraction}def (34){(3)(4)fraction}def (13){(1)(3)fraction}def (23){(2)(3)fraction}def (18){(1)(8)fraction}def (38){(3)(8)fraction}def (58){(5)(8)fraction}def (78){(7)(8)fraction}def (sr){gsave 0 .06 dm rmoveto(\326)show oce}def (is){gsave 0 .15 dm rmoveto(\362)show oce}def (->){gsave 0 .02 dm rmoveto(\256)show oce}def (<-){gsave 0 .02 dm rmoveto(\254)show oce}def (==){gsave 0 .05 dm rmoveto(\272)show oce}def end % an attempt at a PostScript FONT to implement ditroff special chars % this will enable us to % cache the little buggers % generate faster, more compact PS out of psdit % confuse everyone (including myself)! 50 dict dup begin /FontType 3 def /FontName /DIThacks def /FontMatrix [.001 0 0 .001 0 0] def /FontBBox [-260 -260 900 900] def% a lie but ... /Encoding 256 array def 0 1 255{Encoding exch /.notdef put}for Encoding dup 8#040/space put %space dup 8#110/rc put %right ceil dup 8#111/lt put %left top curl dup 8#112/bv put %bold vert dup 8#113/lk put %left mid curl dup 8#114/lb put %left bot curl dup 8#115/rt put %right top curl dup 8#116/rk put %right mid curl dup 8#117/rb put %right bot curl dup 8#120/rf put %right floor dup 8#121/lf put %left floor dup 8#122/lc put %left ceil dup 8#140/sq put %square dup 8#141/bx put %box dup 8#142/ci put %circle dup 8#143/br put %box rule dup 8#144/rn put %root extender dup 8#145/vr put %vertical rule dup 8#146/ob put %outline bullet dup 8#147/bu put %bullet dup 8#150/ru put %rule dup 8#151/ul put %underline pop /DITfd 100 dict def /BuildChar{0 begin /cc exch def /fd exch def /charname fd /Encoding get cc get def /charwid fd /Metrics get charname get def /charproc fd /CharProcs get charname get def charwid 0 fd /FontBBox get aload pop setcachedevice 2 setlinejoin 40 setlinewidth newpath 0 0 moveto gsave charproc grestore end}def /BuildChar load 0 DITfd put %/UniqueID 5 def /CharProcs 50 dict def CharProcs begin /space{}def /.notdef{}def /ru{500 0 rls}def /rn{0 840 moveto 500 0 rls}def /vr{0 800 moveto 0 -770 rls}def /bv{0 800 moveto 0 -1000 rls}def /br{0 750 moveto 0 -1000 rls}def /ul{0 -140 moveto 500 0 rls}def /ob{200 250 rmoveto currentpoint newpath 200 0 360 arc closepath stroke}def /bu{200 250 rmoveto currentpoint newpath 200 0 360 arc closepath fill}def /sq{80 0 rmoveto currentpoint dround newpath moveto 640 0 rlineto 0 640 rlineto -640 0 rlineto closepath stroke}def /bx{80 0 rmoveto currentpoint dround newpath moveto 640 0 rlineto 0 640 rlineto -640 0 rlineto closepath fill}def /ci{500 360 rmoveto currentpoint newpath 333 0 360 arc 50 setlinewidth stroke}def /lt{0 -200 moveto 0 550 rlineto currx 800 2cx s4 add exch s4 a4p stroke}def /lb{0 800 moveto 0 -550 rlineto currx -200 2cx s4 add exch s4 a4p stroke}def /rt{0 -200 moveto 0 550 rlineto currx 800 2cx s4 sub exch s4 a4p stroke}def /rb{0 800 moveto 0 -500 rlineto currx -200 2cx s4 sub exch s4 a4p stroke}def /lk{0 800 moveto 0 300 -300 300 s4 arcto pop pop 1000 sub 0 300 4 2 roll s4 a4p 0 -200 lineto stroke}def /rk{0 800 moveto 0 300 s2 300 s4 arcto pop pop 1000 sub 0 300 4 2 roll s4 a4p 0 -200 lineto stroke}def /lf{0 800 moveto 0 -1000 rlineto s4 0 rls}def /rf{0 800 moveto 0 -1000 rlineto s4 neg 0 rls}def /lc{0 -200 moveto 0 1000 rlineto s4 0 rls}def /rc{0 -200 moveto 0 1000 rlineto s4 neg 0 rls}def end /Metrics 50 dict def Metrics begin /.notdef 0 def /space 500 def /ru 500 def /br 0 def /lt 416 def /lb 416 def /rt 416 def /rb 416 def /lk 416 def /rk 416 def /rc 416 def /lc 416 def /rf 416 def /lf 416 def /bv 416 def /ob 350 def /bu 350 def /ci 750 def /bx 750 def /sq 750 def /rn 500 def /ul 500 def /vr 0 def end DITfd begin /s2 500 def /s4 250 def /s3 333 def /a4p{arcto pop pop pop pop}def /2cx{2 copy exch}def /rls{rlineto stroke}def /currx{currentpoint pop}def /dround{transform round exch round exch itransform} def end end /DIThacks exch definefont pop ditstart (psc)xT 576 1 1 xr 1(Times-Roman)xf 1 f 2(Times-Italic)xf 2 f 3(Times-Bold)xf 3 f 4(Times-BoldItalic)xf 4 f 5(Helvetica)xf 5 f 6(Helvetica-Bold)xf 6 f 7(Courier)xf 7 f 8(Courier-Bold)xf 8 f 9(Symbol)xf 9 f 10(DIThacks)xf 10 f 10 s 1 f xi %%EndProlog %%Page: 1 1 10 s 10 xH 0 xS 1 f 7 f 12 s 720 688(Network)N 1184(Working)X 1648(Group)X 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1050(padding)X 1387(characters,)X 1829(or)X 1936($3$)X 2075(the)X 2220(\256nal)X 2418(quantum)X 2782(of)X 2889(encoding)X 3269(input)X 3493(is)X 3583(exactly)X 3888(16)X 4010(bits;)X 720 4576(here,)N 956(the)X 1120(\256nal)X 1337(unit)X 1533(of)X 1659(encoded)X 2026(output)X 2318(will)X 2514(be)X 2651(three)X 2890(characters)X 3327(followed)X 3715(by)X 3858(one)X 4044("=")X 720 4688(padding)N 1054(character.)X 720 4912(Because)N 1079(it)X 1171(is)X 1273(used)X 1488(only)X 1698(for)X 1849(padding)X 2198(at)X 2307(the)X 2464(end)X 2642(of)X 2761(the)X 2918(data,)X 3142(the)X 3299(occurrence)X 3761(of)X 3880(any)X 4058(\302=')X 720 5024(characters)N 1143(may)X 1341(be)X 1464(taken)X 1705(as)X 1817(evidence)X 2192(that)X 2369(the)X 2519(end)X 2690(of)X 2802(the)X 2952(data)X 3145(has)X 3305(been)X 3519(reached)X 3850($without)X 720 5136(truncation)N 1135(in)X 1234(transit$.)X 1579(No)X 1720(such)X 1920(assurance)X 2318(is)X 2407(possible,)X 2771(however,)X 3151(when)X 3384(the)X 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2144(been)X 2354(converted)X 2762(to)X 2865(canonical)X 3263(form.)X 3502(In)X 3610(particular,)X 4031(text)X 720 912(line)N 912(breaks)X 1210(must)X 1444(be)X 1582(converted)X 2009(into)X 2206(CRLF)X 2493(sequences)X 2930(prior)X 3164(to)X 3286(base64)X 3601(encoding.)X 4026(The)X 720 1024(important)N 1126(thing)X 1355(to)X 1461(note)X 1658(is)X 1753(that)X 1929(this)X 2099(may)X 2296(be)X 2418(done)X 2636(directly)X 2962(by)X 3089(the)X 3238(encoder)X 3574(rather)X 3830(than)X 4027(in)X 4133(a)X 720 1136(prior)N 931 0.2542(canonicalization)AX 1588(step)X 1767(in)X 1866(some)X 2093(implementations.)X 2 f 1000 1360(NOTE:)N 1312(There)X 1571(is)X 1670(no)X 1802(need)X 2020(to)X 2131(worry)X 2396(about)X 2651(quoting)X 2981(apparent)X 3364(encapsulation)X 1000 1472(boundaries)N 1469(within)X 1747(base64-encoded)X 2409(parts)X 2642(of)X 2753(multipart)X 3147(entities)X 3462(because)X 3808(no)X 1000 1584(hyphen)N 1302(characters)X 1737(are)X 1889(used)X 2089(in)X 2188(the)X 2330(base64)X 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1360(Appendix)N 1363(H)X 1456(--)X 1544(Changes)X 1899(from)X 2110(RFC)X 2315(1341)X 2520(...............................................................)X 4080(68)X 960 1472 0.0467(References........................................................ ......................................................)AN 4080(69)X 720 6160(Borenstein)N 1161(&)X 1260(Freed)X 3820([Page)X 4063(iii])X 75 p %%Trailer xt xs

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