[First, three links:
• The current puzzle 
• Our puzzle-solving guidelines 
• A Nation puzzle–solver’s blog  where you can ask for and offer hints, and where every one of our clues is explained in detail.]
Every clue in a cryptic crossword has two parts—definition and wordplay—but that doesn’t mean they’re created equal. On the contrary, there’s a subtle but clear hierarchy between the two components of a clue, and it rears its head periodically to affect and constrain the possibilities of a clue’s structure.
The basic idea underlying any cryptic clue is that the solver’s goal is to arrive at the answer—and the answer is represented in the clue by the definition. The wordplay should be thought of as a tool that’s useful in reaching that goal. Solvers anagram letters or concatenate shorter words or say homophones out loud in order to arrive at the answer word—not vice versa.
This makes sense if you think about it: Aside from the undeniable pleasure that comes from grasping the workings of each clue (which we discussed in a blog post  a couple of weeks ago), why anagram the letters of an answer, say, once you already know what it is? The logic connecting wordplay and definition flows in a specific direction, and a clue should reflect that—or at least, not violate it.
Note that this is more a philosophical point than a reflection of the actual solving process. In the real world, solvers often derive the answer to a clue from the definition, which can be the easiest way in if you have some information from the grid (a point we touched on here ). But the underlying principle remains, which is that solving is in essence a search for the answer word.
Many, if not most, clues are neutral on this point. A clue, for example, may simply juxtapose the definition and wordplay in either order:
NUTCASE Sean cut crumbling fruitcake (7)
DOPER Perform for each druggie (5)
Or it may assert an equivalence between the two—and equivalence is symmetrical by its nature:
ACRONYM In the morning hours, friend is AWOL, for instance (7)
GINSENG Tea is liquor’s twin (7)
But the tricky part comes when the two parts of a clue imply a sense of direction, or logical priority. We make a practice of rejecting or revising clues that point in the wrong direction—that suggest, for instance, that the answer would yield the wordplay, or that the wordplay would be derived from the answer.
The most common flags for such clues include the connectors “for” (implying “perform the processes of the wordplay for the answer” and “from” (as in “derive the answer from the wordplay”). Here are some clues that could not have been done in reverse order.
TOURIST Trout is stewed for visitor (7)
CUPID Athletic supporter with label for naked boy (5)
ARTISTS Musicians, perhaps from Dire Straits (7)
INFLOW Revenue from news, mostly meager (6)
As with most things, we regard this as more of a guideline than an ironclad law—something we generally observe unless there’s a really good reason to violate it (or we forget). But it does help to add consistency and structure to the clue-writing process.
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