bpm's Operations Room

all language features are defined in... the language file!
Opera works in all sorts of languages - and there's no English on screen in most of them. So any language you'd like to change is being generated by a file somewhere on your system; in fact, the LNG file. Which you can edit. Pop it open in Opera (set to open LNG files via Prefs/Advanced/Downloads) or another text editor, search for the term you don't like, comment out the line and type in the replacement. (Found at C:\program files\opera\locale\en\en.lng for example.) A feeling of calm, order: it is not beyond our control!

how to get keystrokes listed on menus?
They are generated automatically, from a comparison of menu & keyboard assignments. So you can't specify them, but if you make sure the functions are specified in the same way in both menu.ini and kb.ini they will usually appear.

invisible tooltip-suppressor bar
Empty-but-enabled status bar is invisible but suppresses URL tooltips anyway. I learned this from Wandering Electrons (via this thorough writeup in his blog), who learned it from that fount of Opera lore, SGunhouse.

status field scope depends on location
status field on page-specific toolbar (those below tab bar, such as Address Bar) doesn't show URLs when tabs are hovered; status field on browser-specific toolbar (Main or Status - the ones above tab bar) does.

select without triggering: the "smear" gesture
how do you move selection to a bookmark without launching it? The answer is one of Pesala's tips: move sideways between mousedown and mouseup, turning the gesture from a click into something else - a gesture many (most?) people aren't aware of, which has (so far as I know) no established name. Actually relevant much more broadly - not just in Opera.

Ctrl+drag to copy
Drag moves, Ctrl+drag copies. Absorb that to become a list-management maestro (works for notes & bookmarks, as well as files & folders outside of Opera; not for text).

drag pulls scattered items together
select a disjoint set of items (bookmarks or notes to be assembled into a folder or tabs to be gathered into a new window, for example) using Ctrl+click: then a drag-and-drop will pull them all together in one spot. Even a little nudge, not enough to move the particular item you're nudging out of its current position: still enough to bring all the others to it. Absorb this and sorting is a snap.

how to detach & re-attach pages
Drag-tab-or-link-to-desktop I knew about, but that requires non-maximized Opera window. This item in Tamil's blog taught me that drag-to-titlebar (available with Opera maximized) also works - and that re-attachment (a stumper, because there is no command for it) can be done by drag within Windows panel.

PrintScreen key puts a screenshot on the clipboard
I think I remained unaware of this until unusually late in my computer life. Just never encountered it - and never bothered with screenshots, thinking they were something complicated. PrintScreen to capture, Irfanview to convert to compressed format & get rid of bitmap bulk (and also crop): it's really a snap. And another Pesala tip - the clippaste parameter- makes it even quicker. Also worth knowing Alt+PrintScreen captures only the active window.

Forum-post update workaround: use an image
Can't edit a forum post after one day - but if you included an image, you can change the image file the tag points to. So... take a screenshot of text you may want to update, and include it in your post as an image. A way to keep the headline post up to date.

double click last URL segment to select URL
Opera uses an offbeat rule for text selection with doubleclick: "highlight forward to next separator, back to last space or linebreak." If you know this, you can highlight a URL with a doubleclick - which I imagine is the intention (though if it's not explained you have to stumble into it). Here's a demo:
abc.defg,hijk?lmnop!qrst;uv:wxyz
Try doubleclicking at various locations in that to verify the rule.
update: not in 9.5.

to customize forum listings, edit and bookmark querystrings
An application of the principle behind saved searches in general. Here's the standard querystring for "my active topics"; changing red variables gives listing for shorter or longer period, different user, or listing of posts instead of threads. For example, I have a bookmark that generates list of my posts, past month, so I can refer to them easily.
http://my.opera.com/community/forums/myactive.dml?username=bpm&exactusername=Y&datemodifier=newer&limitdate=7&sortby=last&disp=thread&mode=forum
Can bookmark topic searches too - creating folder of topics you track, if you like.

suspend insert mode to issue commands
Wish: to be able to use familiar keystroke commands while in an editing field (notes, forum post, sourceview) - where they normally cause characters to be inserted. (For example: b,p is personal bar toggle.) Solution is based on fact that Opera accepts multi-tap commands: set up a prefix tap that in effect switches from insert mode to command mode. I use Ctrl+b (for Block): then Ctrl+b, followed by familiar command sequence, can be assigned to generate the familiar function in edit mode: "b Ctrl,b,p = view personal bar,6 | view personal bar,0"

data URLs: what a concept!
When I started making dummy pages in order to use their tabs as folders and and headings on the tab bar, AyushJ pointed out that they could be generated by data URLs - URLs which don't point to a page, but instead contain the data which defines one - eliminating the need for files. Here's one: data URL specimen - hover to see the URL, click to see what it does.

shortcuts automatically maintain modifier "open where?" pattern
Commands which open a window (Hotclick Search, for example) - if assigned to a keystroke with Shift, will open in new window; if keystroke with Shift+Ctrl, in background. Maintains the pattern established for Enter and leftclick - but who knew? (Well, SGunhouse did - mentioned it here.)

inserting the "uninsertable" characters
Pointed out by Shoust, brought to my attention by Ayush. I was stumped regarding how to get quotation marks and linebreaks into "insert" commands - but the "convert hex to Unicode" function can handle it. So now you can, for example, write a macro that inserts a multi-line address or sig. (If we just had a manual... but in fact we're piecing one together.)

generating Unicode
what the "convert hex to Unicode" function is mainly for: type the hex, then tap your Convert key to get the Unicode symbol: 2230 becomes ∰, for example; charts here.