Write protection
protection for the overwriting of data
Write protection is any physical mechanism that prevents writing, modifying, or erasing data on a device. Most commercial software, audio and video on writeable media is write-protected when distributed.
Examples
IBM 1⁄2-inch magnetic tape reels, introduced in the 1950s, had a circular groove on one side of the reel, into which a soft plastic ring had to be placed in order to write on the tape. ("No ring, no write.")
Audio cassettes and VHS videocassettes have tabs on the top/rear edge that can be broken off (uncovered = protected).
8 and 5+1⁄4-inch floppies can have, respectively, write-protect and write-enable notches on the right side (8-inch punched = protected; 5+1⁄4-inch covered/notch not present = protected). A common practice with single-sided floppies was to punch a second notch on the opposite side of the disk to enable use of both sides of the media, creating a flippy disk, so called because one originally had to flip the disk over to use the other side.
3+1⁄2-inch floppy disks have a sliding tab in a window on the right side (open = protected).
Iomega Zip disks were write-protected using the IomegaWare software.
Syquest EZ-drive (135 & 250 MB) disks were write-protected using a small metal switch on the rear of the disk at the bottom.
VHS-C, Video8, Hi8, and DV videocassettes have a sliding tab on the rear edge.
The public source identifies “Write protection” as protection for the overwriting of data. This brief keeps that definition visible, then builds a research path around Write, protection and overwriting.
Why this record matters
A short description can identify a subject without explaining its stakes. For “Write protection”, the useful work is to connect “protection for the overwriting of data” to the records capable of establishing context and consequence.
Vocabulary and entity names are the principal evidence signals here, because they determine the precision of every later search. The source revision retrieved here is dated Aug 15, 2026. The linked authority identifier is Q1421612. None of the 0 selected statements returned an explicit reference.
The absence of detail may reflect summary conventions rather than a lack of surviving documentation. The lead is largely declarative, so disagreement and counter-evidence require a deliberate search beyond the opening account. Authority statements aid reconciliation but still require their own references, qualifiers and ranks to be checked.
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Three-step research path
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Questions for further research
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This entry incorporates text from “Write protection” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.