I have read on the internet that the primary record for a domain (eg example.com) should be an A record, and that bad things happen if you use a CNAME record.  I work for a web company that has several clients. Each client has their business domain (which they typically own), but I wanted to be a) able to update the server their site is hosted on without contacting them and b) have an alternate domain to access all their sites on.  The company I work for has a domain that I control, eg mycompany.com  To this end, for each client, I have created eg (client1.mycompany.com, client2.mycompany.com) records that point to our server that hosts the websites.  Now, since many clients own their own domains, I ask the clients IT person to create a CNAME record for clientdomain.com that points to client1.mycompany.com. This allows me to update the IP address that client1.mycompany.com points to without involving the clients IT person because all they have is a CNAME record that points to something I control.  This appears to work.  However, I have read that creating a CNAME record as the primary record can lead to issues with email (some of these domains have MX records but typically the client has their own mailserver). The information I read didn't really go into much detail and I didn't quite understand it.  Can someone please elaborate on why setting a CNAME record as the primary record is considered a bad idea, as it seems to work?
Is it possible to set a CNAME record at the top of a domain? (i.e. @ CNAME www, @ CNAME foobar.com., etc.)  My ISP says that it's only possible to use CNAME's for subdomains but I've read somewhere else that is should be possible even if not recommended.
What rules govern forced removal from flights (due to overbooking)? I was recently surprised to see  because his flight was overbooked.  He was reportedly a doctor who needed to see patients the next morning, so he did not really want to get off, justifying the use of force.  I knew that airlines could overbook flights and deny boarding to some passengers, but I thought that kind of boarding denial would happen at the gate and that once folks had been let on, those denied boarding would be those arriving later to the gate.    Why or in what conditions is this kind of forcible removal considered OK?    Clarification following close votes from people who think this question is primarily opinion-based: By "OK" I mean the sense of "legally OK," "officially accepted," "instantiated as policy," "sanctioned by authorities," or "OK according to the regulations and policies and laws and whatever other formal rules govern forced removal from flights due to overbooking." Whether or not you personally consider it socially acceptable does not matter as an answer, unless you have formalized that into a citeable adopted form that governs what happens and want to explain the reasoning behind that rule. How to set Command Block(s) to test for a particular time and output a message? I simply want one command block to test for the time of day or night (e.g. time = 18000) and output a message in the chat to everyone if that time returns true.  I was trying a simple set-up with two command blocks and a comparator in the middle, but I'm a beginner and am obviously missing the correct syntax (especially to test for a particular time of day, and if true, then trigger the say "message" block).  ETA: Kudos to @Ben for the Daylight Sensor/Redstone idea, but I'd really prefer a Command Block solution for the above, since my plan is to output several messages during the day and night cycle at very specific times in the world. Thanks. EPSG:4326 being saved as CRS:84 Interpolation of multibeam bathymetry using ArcGIS Desktop? I'm trying to make a 3D map with multi-beam bathymetry (65536 features, xyz), but it seems that the interpolation methods are too rigid. I need to smooth the data so it looks more natural and realistic.   Which parameters do I have to vary so I can get this? How can blackbody radition be explained by quantization? I don't understand why quantization makes a peak on the blackbody radiation curve (so there is no ) and the relationship between that peak and quantization concept.  When the blackbody is heated, it starts to glow. All atoms start to vibrate. Total heating energy must be divided and equally shared by all atoms of blackbody. Right?  But what happens next?  Do some atoms get much more energy to radiate at higher frequency and waste the energy? What happens at the atomic level, so quantization can explain it? What does classical physics claim, so it can not explain the radiation curve? Are the tags shown in a particular order? I have a small Problem that occurs from time to time.   Sometimes, when I copy things or when I put an object from the symbol library on my page, the whole file gets messed up. The screenshot shows it. I make the graphic on the right, Illustrator the ones on the left.   I have pixel snapping checked. Is there a way to tell Illustrator to align everything to pixels no matter what? Database design for products with bundles of products I am building a database system for my retail business. I have set some tables which are:   Product Purchase Sales Balance   All are connected one another and are able to show my inventory level.  The problem I am having is I also sell bundles of products - that have different prices than their individual prices. Example: I sell an orange for $1, an apple for $1.2; I sell fruit package 1 (2 oranges and 2 apples) for $3.8, package 2 (4 oranges and 4 apples) for $7.  Is there a right way how to create relationship for these product bundles?  PS: I am using FileMaker Pro creating this. If I can generally reach web pages on the Internet but can't reach a specific one, how do I troubleshoot what the cause is as an end user?       This question was a .   Read the  for more details or  yourself Can we define flat connection on any given smooth manifold? For example, a sphere $S^2$ in $\mathbf{R}^3$ is apparently not flat with respect to the Euclidean connection, but can we define a flat connection and thus with affine charts on $S^2$? Purpose of else and finally in exception handling Modifying agsm.bst package bibliography output I would like to change the URL output from:  URL: the html link  into:  [Online]URL: [Accessed on]  I am using:  \usepackage[comma]{natbib} \bibliographystyle{agsm} How to add “jQuery” onclick functionality for a column each row in jQgrid to display different popups for different rows If $A+B=AB$ then $AB=BA$ I was doing the problem $$ A+B=AB\implies AB=BA. $$  $AB=BA$ means they're invertible, but I can't figure out how to show that $A+B=AB$ implies invertibility. What are the biggest changes between UA Ranger and PHB Ranger? What is the use case for a Fragment with no UI? How can you get the names of method parameters? If I have a method such as:  public void MyMethod(int arg1, string arg2)   How would I go about getting the actual names of the arguments? I can't seem to find anything in the MethodInfo which will actually give me the name of the parameter.  I would like to write a method which looks like this:  public static string GetParamName(MethodInfo method, int index)   So if I called this method with:  string name = GetParamName(MyMethod, 0)   it would return "arg1". Is this possible? I can see by manipulating the expression why $\mathbb{E}X$ works out to be $\int_0^\infty 1-F(x)\,dx$, where $F$ is the distribution function of $X$, but what is an intuitive explanation for why that is true? If at each point we sum the probability $\mathbb{P}(X&gt;x)$, why should we end up with the expectation?  Thanks How does Mathematica integrate? Should 'drive by' downvoting be more effectively caught? I have an answer that I'm certain is technically correct. However, it continues to be downvoted. The answer has already been noted in comments on other answers to be better. It goes more in-depth than the others, yet it continues to be downvoted.  The already upvoted answers were nowhere close initially, and I had already commented on them to say why it is wrong...  Isn't there a limit for that? Shouldn't something be catching this?