There are two issues that need to be fixed on the Supported macros documentation page:

1) {ITEM.*} indexed macros should mention item instead of host in the description part "This macro may be used with a numeric index e.g. {ITEM.ID<1-9>} to point to the first, second, third, etc. host in a trigger expression." (happens to almost all of them)

2) {ITEM.LOG.TIMESTAMP} (and also {ITEM.LOG.TIME}, {ITEM.LOG.DATE}, {ITEM.LOG.AGE}) could explain better if this is time when event happens or collection time of log value