If you try to delete a useless usage guidance excerpt, you can't save the edit, because you get an error message that "Wiki Excerpt is missing." No kidding. That's the whole point!  Why is the excerpt absolutely required once it is ever populated, even for tags that are reasonably self-descriptive? It's nice to want to have guidance for every tag, but often it's far more practical to just rely on the tag name, and stopping an editor in their tracks can be harmful if they're just trying to help by clearing away guidance that's outright counterproductive. For example,  on ELL: "For questions that use the word 'which'." How about we not include  in that, OK? In cases like this, it would be far better to have nothing at all than to have that bit of drivel.  Even . Please allow editor discretion, rather than enforcing an inconsistently and unrealistically high standard for fixes to terrible excerpts.
Sometimes a tag wiki excerpt or body ends up with unacceptable or useless content: plagiarized text that must be removed, or a totally unhelpful dictionary definition. (For example:  — and I've seen this situation many times before.)  The only way to get rid of that content is to submit replacement text that meets the minimum length requirement. This is not always easy as writing a decent wiki, and especially a decent excerpt, requires subject knowledge.  Currently the users or even moderators who are alerted to unacceptable content in a tag wiki cannot remove that content without providing their own, which they are not always in a position to do. Yet these wikis would be better off with no content than with either unacceptable or unhelpful content, or some content written by a non-expert in a hurry.  Please provide a way for users to blank a tag wiki excerpt or body. I'm not sure what the reputation requirement should be: same mechanism as for tag wiki edits (suggested edits with approval), or only done directly by a user with the trusted user (20k) privilege, or moderator-only.
How do I install Ubuntu Server (step-by-step)? I'd like to install Ubuntu server on my machine, is there a step-by-step instructions on how to accomplish that or a guide that will just go through the basic steps of installing Ubuntu Server from beginning to end.  Instructions originally for 13.04. How to start a new Linux distro? Tikz shortandoff-on newcommand problem Usually I have no problem with babel and !:, and I don't use shortandoff-on switch. But since I made a command using !#1 parameter, the problem comes up again.  The same synthax used outside the command work fine, but in the command I get the error message :  ! Package tikz Error: + or - expected.  How to solve the problem without using the shortandoff-on switch ?  \documentclass[french,a4paper]{article} \RequirePackage{etex} \RequirePackage[utf8]{inputenc} \RequirePackage[T1]{fontenc} \RequirePackage{fourier}  \RequirePackage{tikz} \usetikzlibrary{calc,intersections}  %%%%%%%%%%%%%%%%%%%%%% %%%% Francisation %%%% %%%%%%%%%%%%%%%%%%%%%%  \RequirePackage{babel}  %%%%%%%%%%%%%%%%%%% ---------------------------------------- %%%% Géométrie %%%% %%%%%%%%%%%%%%%%%%%-----------------------------------------      % #1 option du path     % #2 premier point     % #3 second point     % #4 longueur dans un sens     % #5 longueur dans l'autre     % défini Mil#1#2 \newcommand{\Med}[5][]{%     \path[#1,name path=Med#2#3] ($(#2)!.5!(#3)$) node (Mil#2#3) {}      ($(Mil#2#3)!#4!90:(#3)$) -- ($(Mil#2#3)!#5!270:(#3)$) ; }  \tikzset{small dot/.style={fill=black,circle,scale=0.3}}  \begin{document}  %\shorthandoff{:!} \begin{tikzpicture}  \coordinate[label=below left:$A$] (A) at (0,0) ; \coordinate[label=below right:$B$] (B) at (4,0) ;  \draw (A)--(B) ;  %\Med[draw]{A}{B}{1}{1} ;  \draw($(A)!.5!(B)$) node (MilAB) {}      ($(MilAB)!1!90:(B)$) -- ($(MilAB)!1!270:(B)$) ;   \end{tikzpicture} %\shorthandon{:!}  \end{document} Is there any anti-gravity material? I want to know if there is any  material. I am thinking of making flying vehicles which are made up of anti-gravity material so that they will not experience any gravity on them and can easily take off and be more fuel efficient. Is there any such thing? Or any workaround? Work done in adiabatic process I have the following code:  \documentclass[a4paper,12pt]{article} \usepackage[margin=2cm]{geometry} %showframe \begin{document} \tableofcontents \newpage \section*{Abstract} \section{Introduction} \newpage \bibliographystyle{apacite} \bibliography{references} \end{document}   And when I create the table of contents it adds the "References" in the TOC, how can I remove this to not be included in TOC? So far I have tried something like   \bibliography*{references} How to move a visible file to a hidden folder? I've only been using Ubuntu for two weeks and have been able to find answers to any problem I had, however this one defies my searches.  I want to move a visible programme file (wallch) to a hidden directory ./config/autostart.  I have been able to enter this directory and the subject file is not there and I want to have this program start at bootup.  Can anyone assist?  Thanking you Get all possible partitions of number Is there a way to get all possible partitions of an integer? Possibly specifying max and/or min summand. I'm interested in partitions themselves, not just partition count. Calculate the sum of inverse values of ${n\choose 0}, {n\choose 1}, ... {n\choose n}$ Calculate $$A={1\over {n\choose 0}}+ {1\over {n\choose 1}}+ ...+{1\over  {n\choose n}}$$  and  $$B={1\over {n\choose 0}}- {1\over {n\choose 1}}+ ...+{(-1)^n\over  {n\choose n}}$$     My idea for $A$ is some probabilistic reasoning. Color the sets $$\{\}, \{1\}, \{1,2\}, \{1,2,3\},...\{1,2,...,n\}$$ and ask our self what is the probability that I choose colored set among all sets. Clearly this is exactly ${n+1\over 2^n}$ and on the other side it is $A$:  probability that I take empty set is ${1\over {n\choose 0}}$,   probability that I take colored set with 1 element is ${1\over {n\choose 1}}$  probability that I take colored set with 2 elements is ${1\over {n\choose 2}}$  and so on ...   So $A ={n+1\over 2^n}$. But I have no idea how to attack $B$. How to share files through the local network? Update manager doesn't offer an upgrade to the new release "spent a lot of time to shop" vs. "spent a lot of time shopping" She spends a lot of time to shop. She spends a lot of time shopping.   Are both of these sentences grammatically correct and do they have the same meaning? if recursively find ext, then, else on unix This is what I normally use. But I need to recursively find an extension with, then, and else. The problem with this one is that it is not recursive.  if ls $HOME/Downloads/*.ext &gt;/dev/null 2&gt;&amp;1 then     : else     : fi "Fatal error: Cannot redeclare " Limit of derivative is zero. Does it imply a limit for f(x)? The context is soccer (association football) and the sentence in question is:       The forward received the ball from the midfielder's pass.     I have already ask about this  and received alot of good answers, and I tried to leave it at that.  But then the World Cup 2014 is upon us, and I am starting to have doubts about this football usage of "from", to the point that I have semi-nightmares about it.  The use of "from" in the football example continues to bother me.  I seem to disagree (subconsciously) about how a ball (physical object) could be "from" a pass (action) unless that action creates that object.       Some people were hit by debris from the explosion.   The use of "from" in "debris from the explosion" makes excellent sense to me, because the explosion does create the debris.  But in soccer/football, the ball cannot possibly be "created" by a pass.    Is there any non-football usage of "from" similar to my football example sentence? I have a table:  table votes (     id,     user,     email,     address,     primary key(id), );   Now I want to make the columns user, email, address unique (together).  How do I do this in MySql?  Of course the example is just... an example. So please don't worry about the semantics. Sum of items in a collection I understand that information cannot be transmitted at a velocity greater than speed of light. I think of this in terms of the radio broadcast: the station sends out carrier frequencies $\omega_c$ but the actual content is carried in the modulated wave, the sidebands $\omega_c\pm\omega_m$. The modulation envelop has its group velocity and this is the speed at which information is being transmitted. We also know, for example, that x-rays in glass have a phase velocity which is greater than the speed of light in vacuum.   My question is, what exactly is it that is travelling faster than the speed of light?    EDIT: I know it couldn't be anything physical as its superluminal. My problem is, what is it that has absolutely no information content yet we associate a velocity with it. Can I extend a class using more than 1 class in PHP? If I have several classes with functions that I need but want to store separately for organisation, can I extend a class to have both?  i.e. class a extends b extends c  edit: I know how to extend classes one at a time, but I'm looking for a method to instantly extend a class using multiple base classes - AFAIK you can't do this in PHP but there should be ways around it without resorting to class c extends b, class b extends a