In the log file, they are not expanded as they are here.
Occasionally, they references something like shockwave, but most are this kind of "statistical" message.
1/26/13 2:58:50.713 PM Safari[1355]: Window count
com.apple.message.domain: com.apple.Safari.WindowCount
com.apple.message.value: 1
1/26/13 2:58:50.714 PM Safari[1355]: Tabs per window count
com.apple.message.domain: com.apple.Safari.TabsPerWindowCount
com.apple.message.value: 1
1/26/13 2:58:51.717 PM Safari[1355]: Items modified in last hour
com.apple.message.domain: com.apple.Safari.History.ItemsModifiedIn1Hour
com.apple.message.value: 32
com.apple.message.summarize: YES
1/26/13 3:07:44.683 PM Safari[1355]: Web Page visited
com.apple.message.domain: com.apple.Safari.PageVisited
com.apple.message.summarize: YES
1/26/13 3:07:51.184 PM Safari[1355]: Web Page visited
com.apple.message.domain: com.apple.Safari.PageVisited
com.apple.message.summarize: YES
1/26/13 3:07:51.840 PM Safari[1355]: Web Page visited
com.apple.message.domain: com.apple.Safari.PageVisited
com.apple.message.summarize: YES
1/26/13 3:08:01.389 PM Safari[1355]: Web Page visited
com.apple.message.domain: com.apple.Safari.PageVisited
com.apple.message.summarize: YES
1/26/13 3:08:05.677 PM Safari[1355]: Web Page visited
com.apple.message.domain: com.apple.Safari.PageVisited
com.apple.message.summarize: YES
1/26/13 3:08:21.102 PM Safari[1355]: Back button clicked
com.apple.message.domain: com.apple.Safari.BackForward
com.apple.message.signature: back
com.apple.message.summarize: YES
1/26/13 3:08:21.713 PM Safari[1355]: Web Page visited
com.apple.message.domain: com.apple.Safari.PageVisited
com.apple.message.summarize: YES
1/26/13 3:08:23.207 PM Safari[1355]: Back button clicked
com.apple.message.domain: com.apple.Safari.BackForward
com.apple.message.signature: back
com.apple.message.summarize: YES
1/26/13 3:08:26.909 PM Safari[1355]: Web Page visited
com.apple.message.domain: com.apple.Safari.PageVisited
com.apple.message.summarize: YES
1/26/13 3:08:38.567 PM Safari[1355]: Web Page visited
com.apple.message.domain: com.apple.Safari.PageVisited
com.apple.message.summarize: YES
1/26/13 3:09:08.540 PM Safari[1355]: Web Page visited
com.apple.message.domain: com.apple.Safari.PageVisited
com.apple.message.summarize: YES
1/26/13 3:09:31.014 PM Safari[1355]: Web Page visited
com.apple.message.domain: com.apple.Safari.PageVisited
com.apple.message.summarize: YES
1/26/13 3:09:31.619 PM Safari[1355]: Web Page visited
com.apple.message.domain: com.apple.Safari.PageVisited
com.apple.message.summarize: YES
1/26/13 3:09:51.035 PM Safari[1355]: Bookmark visited
com.apple.message.domain: com.apple.Safari.BookmarkVisited
com.apple.message.signature: bookmark
com.apple.message.summarize: YES
1/26/13 3:09:51.882 PM Safari[1355]: Web Page visited
com.apple.message.domain: com.apple.Safari.PageVisited
com.apple.message.summarize: YES
1/26/13 3:09:59.817 PM Safari[1355]: Web Page visited
com.apple.message.domain: com.apple.Safari.PageVisited
com.apple.message.summarize: YES
1/26/13 3:10:08.996 PM Safari[1355]: Web Page visited
com.apple.message.domain: com.apple.Safari.PageVisited
com.apple.message.summarize: YES
1/26/13 3:24:55.935 PM Safari[1355]: Web Page visited
com.apple.message.domain: com.apple.Safari.PageVisited
com.apple.message.summarize: YES
1/26/13 3:24:58.077 PM Safari[1355]: Web Page visited
com.apple.message.domain: com.apple.Safari.PageVisited
com.apple.message.summarize: YES
1/26/13 3:25:00.146 PM Safari[1355]: Web Page visited
com.apple.message.domain: com.apple.Safari.PageVisited
com.apple.message.summarize: YES
1/26/13 3:25:00.275 PM Safari[1355]: Web Page visited
com.apple.message.domain: com.apple.Safari.PageVisited
com.apple.message.summarize: YES
1/26/13 3:25:18.070 PM Safari[1355]: Web Page visited
com.apple.message.domain: com.apple.Safari.PageVisited
com.apple.message.summarize: YES