{"id":19463,"date":"2009-01-16T10:00:00","date_gmt":"2009-01-16T10:00:00","guid":{"rendered":"https:\/\/blogs.msdn.microsoft.com\/oldnewthing\/2009\/01\/16\/you-cannot-pre-emptively-reserve-a-file-extension\/"},"modified":"2009-01-16T10:00:00","modified_gmt":"2009-01-16T10:00:00","slug":"you-cannot-pre-emptively-reserve-a-file-extension","status":"publish","type":"post","link":"https:\/\/devblogs.microsoft.com\/oldnewthing\/20090116-00\/?p=19463","title":{"rendered":"You cannot pre-emptively reserve a file extension"},"content":{"rendered":"<p>The following question came in from a customer:<\/p>\n<blockquote class=\"q\"><p> If our program isn&#8217;t installed and users double-click our document, they get sent to a Web site that presents a list of programs, but we want to send the user directly to our download site. How do we claim a file extension for our application? <\/p><\/blockquote>\n<p> Um, you don&#8217;t. <\/p>\n<p> You cannot pre-emptively reserve a file extension. If your program uses the extension <code>.ABC<\/code> and somebody off in another country working out of a garage also uses the extension <code>.ABC<\/code>, then that&#8217;s fine. Of course, things get exciting when a user installs both your program and the garage program, but that&#8217;s a conflict for the user to resolve. It is not your position to declare unilaterally that you are more important than that person in a garage. <\/p>\n<p> What you <i>can<\/i> do is list your program among the ones that support the <code>.ABC<\/code> extension, so that when the user double-clicks an <code>.ABC<\/code> document and no program is installed to handle it, <a href=\"http:\/\/blogs.msdn.com\/oldnewthing\/archive\/2009\/01\/13\/9311703.aspx\"> the user is sent to a Web page that includes your program as one which can open that file<\/a>. But this doesn&#8217;t grant you exclusivity. You&#8217;ll just show up on the list with everybody else who wants to claim that file extension. <\/p>\n","protected":false},"excerpt":{"rendered":"<p>The following question came in from a customer: If our program isn&#8217;t installed and users double-click our document, they get sent to a Web site that presents a list of programs, but we want to send the user directly to our download site. How do we claim a file extension for our application? Um, you [&hellip;]<\/p>\n","protected":false},"author":1069,"featured_media":111744,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[1],"tags":[26],"class_list":["post-19463","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-oldnewthing","tag-other"],"acf":[],"blog_post_summary":"<p>The following question came in from a customer: If our program isn&#8217;t installed and users double-click our document, they get sent to a Web site that presents a list of programs, but we want to send the user directly to our download site. How do we claim a file extension for our application? Um, you [&hellip;]<\/p>\n","_links":{"self":[{"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/posts\/19463","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/users\/1069"}],"replies":[{"embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/comments?post=19463"}],"version-history":[{"count":0,"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/posts\/19463\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/media\/111744"}],"wp:attachment":[{"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/media?parent=19463"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/categories?post=19463"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/tags?post=19463"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}