deleting the last line of a paragraph with |dd|, the paragraph will be
  joined with the next one.

- Changed text is saved for undo.  Formatting is also a change.  Thus each
  format action saves text for undo.  This may consume quite a lot of memory.

- Formatting a long paragraph and/or with complicated indenting may be slow.

==============================================================================
7. Sorting text						*sorting*

Vim has a sorting function and a sorting command.  The sorting function can be
found here: |sort()|, |uniq()|.

							*:sor* *:sort*
:[range]sor[t][!] [b][f][i][l][n][o][r][u][x] [/{pattern}/]
			Sort lines in [range].  When no range is given all
			lines are sorted.

			With [!] the order is reversed.

			With [i] case is ignored.

			With [l] sort uses the current collation locale.
			Implementation details: strcoll() is used to compare
			strings. See |:language| to check or set the collation
			locale. Example: >
				:language collate en_US.UTF-8
				:%sort l
<			|v:collate| can also used to check the current locale.
			Sorting using the locale typically ignores case.
			This does not work properly on Mac.

			Options [n][f][x][o][b] are mutually exclusive.

			With [n] sorting is done on the first decimal number
			in the line (after or inside a {pattern} match).
			One leading '-' is included in the number.

			With [f] sorting is done on the Float in the line.
			The value of Float is determined similar to passing
			the text (after or inside a {pattern} match) to
			str2float() function.

			With [x] sorting is done on the first hexadecimal
			number in the line (after or inside a {pattern}
			match).  A leading "0x" or "0X" is ignored.
			One leading '-' is included in the number.

			With [o] sorting is done on the first octal number in
			the line (after or inside a {pattern} match).

			With [b] sorting is done on the first binary number in
			the line (after or inside a {pattern} match).

			With [u] (u stands for unique) only keep the first