咨询HTML锚标签target属性合法取值的W3C官方参考页面

Great question—this is a common point of confusion when working with link targeting in HTML! Let’s break this down clearly:

W3C-Defined Valid Values (Official Spec) #

The official HTML specification from W3C only recognizes two categories of valid target values:

• Special keyword values (these start with an underscore):
  • _self: Opens the link in the same browsing context (window/tab) as the current one (default behavior)
  • _blank: Opens the link in a new, unnamed browsing context
  • _parent: Opens the link in the parent browsing context of the current one (useful if working with frames)
  • _top: Opens the link in the top-level browsing context (breaks out of all frames)
• Custom browsing context names: Any string that doesn’t start with an underscore. This lets you target a specific named window/tab—if the named context doesn’t exist, the browser creates it; if it does exist, the link loads into that existing context.

What About new window/new page? #

Values like target="new window" or target="new page" aren’t defined in the W3C spec—but most modern browsers will still process them. Here’s why:
Browsers treat these as custom browsing context names (since they don’t start with an underscore). So when you use target="new window", the browser creates a window named new window (yes, spaces are allowed in custom names, though not recommended). If you use the same value again later, it’ll reuse that existing window instead of opening a new one.

The catch? These aren’t part of the official standard. There’s no W3C reference page that documents them as valid values because they’re not spec-compliant—they’re just a browser-compatible quirk.

Why You Should Stick to Spec-Compliant Values #

While non-standard values might work today, they come with risks:

• Browser behavior could change in future updates (since they’re not required to support these)
• Custom names with spaces can cause unexpected issues in older browsers
• They’re less readable for other developers, who might expect standard values or clear custom names

If you want a new window every time, use _blank. If you want to reuse a specific window, pick a clear, space-free custom name like product-details-window.

内容的提问来源于stack exchange，提问作者vr3w3c9