Perhaps it is an acceptable behaviour, don't know.  But I want to note
that when EXINIT is set to `set autoindent' copying and pasting between
xterms do not work as most users expect.  I will use the next sample
text to outline the problem, related with the autoindent feature on vi(1):

(first set: four spaces before each text line)

         1         2         3         4         5         6         7 7
         0         0         0         0         0         0         0 2
---------+---------+---------+---------+---------+---------+---------+--
    line number 1 - set 1
    line number 2 - set 1
    line number 3 - set 1
    line number 4 - set 1

(second set: a <tab> before each text line)

         1         2         3         4         5         6         7 7
         0         0         0         0         0         0         0 2
---------+---------+---------+---------+---------+---------+---------+--
	line number 1 - set 2
	line number 2 - set 2
	line number 3 - set 2
	line number 4 - set 2

When EXINIT is set to `set autoindent', lines pasted in vi(1) are
automatically indented --- as a consequence space before the first
nonblank character on each line in the source text is added to
the previous indentation:

For the first set four additional spaces are added to each line (and
replaced with <tabs> if possible):

    line number 1 - set 1
	line number 2 - set 1
	    line number 3 - set 1
		line number 4 - set 1

For the second set a <tab> is added to each line (eight spaces to the
first one):

        line number 1 - set 2
		line number 2 - set 2
			line number 3 - set 2
				line number 4 - set 2

When EXINIT is NOT set to `set autoindent' copying and pasting to vi(1)
works as most users want:

For the first set:

    line number 1 - set 1    
    line number 2 - set 1 
    line number 3 - set 1 
    line number 4 - set 1 

For the second set:

        line number 1 - set 2  
        line number 2 - set 2 
        line number 3 - set 2 
        line number 4 - set 2

ok... <tabs> are translated to spaces on all lines but the source layout
is preserved.  This translation is an xterm(1) related issue.

I want to discuss this behaviour on the mailing list.  If this behaviour
is considered wrong, I will be glad to open a PR.  I suggest these patches:

For csh users:

--- dot.cshrc	2005-05-08 12:05:59.000000000 +0200
+++ dot.cshrc.proposed	2005-05-08 12:07:08.000000000 +0200
@@ -18,7 +18,6 @@
 
 setenv	EDITOR	vi
 setenv	VISUAL	${EDITOR}
-setenv	EXINIT	'set autoindent'
 setenv	PAGER	more
 
 set path = (~/bin /bin /sbin /usr/{bin,sbin,X11R6/bin,pkg/{,s}bin,games} \

For Bourne shell users:

--- dot.profile	2005-05-08 12:06:02.000000000 +0200
+++ dot.profile.proposed	2005-05-08 12:07:23.000000000 +0200
@@ -15,7 +15,5 @@
 
 EDITOR=vi
 export EDITOR
-EXINIT='set autoindent'
-export EXINIT
 PAGER=more
 export PAGER

(both patches must be applied to files in src/etc/skel)

Cheers,
Igor.