From The ChangeLog
What's new in 6.18 (2014-Aug-01 10:47):
*) sstp - report TLS encryption as well;
*) safe mode - do not allow user with less permissions to disrupt active safe mode;
*) console - print command does not try to reuse item numbers assigned by
previous invocations of 'print' when doing 'print where' or 'print follow',
items are numbered consecutively starting from '0'.
*) console - fix compact export of some partially modified
configuration values;
*) api - use the same syntax for property values as is used in 'print detail'
output, with the exception of numbers, that are not shown with suffixes
(K/M/G/T or bitrate) and are not contracted or separated into digit groups,
and "yes"/"no" values that continue to be reported as "true"/"false".
*) console - show internal numbers in the form returned by 'find' (like *9A0F)
instead of "(unknown)" when configuration refers to
deleted items. This change also applies to API.
*) ipsec - fix addition of default policy template;
*) console - values of type 'nil' were returning 'nil' as result of most
operations. Now it compares less than all values except 'nil'
and 'nothing', and compares inequal to all values except 'nil'.
This was changed to make 'print where' and 'find where' more useful.
An example. Previously the following command
/ip route print where routing-mark!=nosuch
Would not print routes that had no value for 'routing-mark' set, because
(nil != "nosuch") was equal to nil. Now it evaluates to 'true', and this
command will also print all routes that have no 'routing-mark' value set.
*) l2tp - fixed problem on CCR where server responded with wrong source address;
*) console export - put qutes around item names that start with a digit;
*) sntp client - added support for dns lookup of ntp servers;
*) console - when exporting to file, use name ending in '.in_progress', and
rename when export finishes;
*) bridge setups sometimes could crash on CCR devices;
*) fixed port flapping in 1G mode on sfp-sfpplus1 on CRS226;
*) fixed SXT ac model losing it's interface if changing regulatory settings in "routerboard" menu