Editing SD card (section)

===Card security===

====Commands to disable writes====
The host device can command the SD card to become read-only (to reject subsequent commands to write information to it). There are both reversible and irreversible host commands that achieve this.<ref>{{Cite web |last=By |date=2014-01-19 |title=The Tiniest SD Card Locker |url=https://hackaday.com/2014/01/18/the-tiniest-sd-card-locker/ |access-date=2023-01-20 |website=Hackaday |language=en-US}}</ref><ref>{{cite patent |country=US |number=7827370 |status=patent}}</ref>

====Write-protect notch====
[[File:SD card unlocked and locked.svg|thumb|Diagram showing an orange sliding write-protect switch in both the unlocked and locked positions]]
[[File:Vorderseite Sony Tough SF-M64T SDUHSII011CORRklein.png|thumb|upright|Sony Tough Series SD card, one of the few cards on the market without a sliding tab on the write protect notch]]

Most full-size SD cards have a mechanical write-protect switch, a sliding tab over a notch on the left side (viewed from the top, with the beveled corner on the right), that signals to the device to treat the card as read-only. Sliding the tab up (toward the contacts) sets the card to read/write; sliding it down sets it to read-only. However, the switch position is not detected by the card’s internal circuitry.<ref>{{Cite web|url=https://www.sdcard.org/downloads/pls/index.html|title=Simplified Specifications – SD Association, version 3.10, Part 1, Physical Layer, section 4.3.6" Write Protect Management"|website=sdcard.org|access-date=2019-04-11|archive-date=2019-04-11|archive-url=https://web.archive.org/web/20190411015937/https://www.sdcard.org/downloads/pls/index.html|url-status=live}}</ref> Therefore, some devices ignore it, while others allow overrides.{{citation needed|date=September 2023}}

MiniSD and microSD cards lack a built-in notch but can be used with adapters that include one. Cards without a notch are always writable; cards with preloaded content have a notch but no sliding tab.{{citation needed|date=September 2023}}

====Card password====
{{more citations needed|section=yes|date=September 2023}}
[[File:Sdadaptersandcards.jpg|thumb|MicroSD-to-SD adapter (left), microSD-to-miniSD adapter (middle), microSD card (right)]]

A host device can lock an SD card using a password of up to 16 bytes, typically supplied by the user.{{citation needed|date=September 2023}} A locked card interacts normally with the host device except that it rejects commands to read and write data.{{citation needed|date=September 2023}} A locked card can be unlocked only by providing the same password. The host device can, after supplying the old password, specify a new password or disable locking. Without the password (typically, in the case that the user forgets the password), the host device can command the card to erase all the data on the card for future re-use (except card data under DRM), but there is no way to gain access to the existing data.{{citation needed|date=September 2023}}

[[Windows Phone 7]] devices use SD cards designed for access only by the phone manufacturer or mobile provider. An SD card inserted into the phone underneath the battery compartment becomes locked "to the phone with an automatically generated key" so that "the SD card cannot be read by another phone, device, or PC".<ref>{{Cite web|url=https://support.microsoft.com/en-us/windows/windows-phone-7-3ebc303c-59c0-d367-3995-f258b184fabb|title=Windows Phone 7 – Microsoft Support|website=support.microsoft.com|access-date=2023-01-22|archive-date=2016-05-03|archive-url=https://web.archive.org/web/20160503105252/http://www.windowsphone.com/en-US/how-to/wp7/basics/copy-and-paste|url-status=live}}</ref> [[Symbian OS|Symbian]] devices, however, are some of the few that can perform the necessary low-level format operations on locked SD cards. It is therefore possible to use a device such as the [[Nokia N8]] to reformat the card for subsequent use in other devices.<ref>{{Cite web|url=https://www.engadget.com/2010/11/17/windows-phone-7s-microsd-mess-the-full-story-and-how-nokia-ca/|title=Windows Phone 7's microSD mess: the full story (and how Nokia can help you out of it)|website=Engadget|date=17 November 2010|access-date=13 October 2019|archive-date=8 August 2019|archive-url=https://web.archive.org/web/20190808215308/http://www.engadget.com/2010/11/17/windows-phone-7s-microsd-mess-the-full-story-and-how-nokia-ca/|url-status=live}}</ref>