|Derived from [Masters2009], 4.4, Structure|
What it is
Structure---in a BDSM sense---is the set of rules, standing orders, and values which a dominant or master gives to his submissive or slave. It provides a context in which the authority of the master or dominant is present and effective even while the dominant or master themselves is away or is not paying active attention to what the slave is doing. By having these rules, standing orders and values the submissive or slave has the continuous guidance or direction of their partner to follow. Without structure being in place, the submissive or slave either may or must choose for themselves, such as what to do, what to wear, etc.. This frequently defeats the purpose of them getting into a D&s or a master/slave relationship in the first place---namely to experience the authority and/or power of their partner.
Beyond making sure the the submissive or slave does what is expected of them, they serve to provide a context of authority in the absence of the dominant or master, and thus give a sense of continuity of control. Such an absence can occur even while the dominant or master is in the room but is not paying attention to the submissive or slave.
Rules provide a slave with explicit directions on what choices to make in a variety of circumstances.
Such a rule might be: "When you are out with friends without me and you are having a meal, if there are dominants at the same table you do not begin to eat or drink until either they have all started eating themselves, or unless one of them directs you or allows you to do so."
Or: "When preparing for a play party, make sure that you wear clothes which are both revealing and which are easy to remove."
While rules don't say explicitly what to do, they give good direction when choices need to be made---such as when to start eating or what clothes to choose from the wardrobe. This gives slaves and submissive confidence that their choices are correct without needing to ask their master.
Standing orders are instructions for a slave or a submissive to follow at particular times or in particular circumstances. They are explicit directions or orders.
For example: "Every morning you will rise before me, prepare a coffee and bring it to me while I am still in bed. Once I have taken the coffee you will go down on your knees beside the bed, lower your forehead to the ground and wait in that position until I tell you to rise."
Or: "When we go to a play party, you will take care of my toybag, including packing it before we go, carrying it to and from the car, ensuring everything is returned to the bag when we leave the party, and making sure everything is clean."
Or: "On Saturdays you do not wear a bra."
Values are a vital, and yet often undermentioned aspect of structure. There will be times when rules and standing orders are not sufficient. A dominant or master may not have foreseen a particular combination of events or circumstances which their slave or submissive needs to deal with in their absence. When the dominant has made an effort to clearly and completely communicate his personal values and priorities to the slave, then the slave is better positioned to make choices which accurately reflect what their dominant would have chosen had they been there. This is also very important where there is an aspect of service present or the submissive or slave is strongly motivated to please their partner. They may even be proud.
Structure only provides continuity
Structure provides continuity only. If the structure is not regularly supported by concrete expressions from the dominant or master, then it will fall to the ground. In other words, structure---no matter how well conceived---is not enough on its own to keep a relationship going. It needs the active involvement of the dominant or master as well. At best structure functions as a bridge between the times the dominant or master is guiding or directing the slave or submissive. If too much time passes between these episodes, structure is not enough to keep the relationship effective. This is not unlike high-tension electrical distribution wiring needing regular support pylons to prevent the wire reaching the ground.