# man > git-check-ref-format(1) > **TLDR:** Check if a reference name is acceptable, and exit with a non-zero status if it is not. > - Check the format of the specified reference name: `git check-ref-format {{refs/head/refname}}` - Print the name of the last branch checked out: `git check-ref-format --branch @{-1}` - Normalize a refname: `git check-ref-format --normalize {{refs/head/refname}}` *Source: tldr-pages* --- [_GIT-CHECK-REF-FORMAT_(1)](https://www.chedong.com/phpMan.php/man/GIT-CHECK-REF-FORMAT/1/markdown) Git Manual [_GIT-CHECK-REF-FORMAT_(1)](https://www.chedong.com/phpMan.php/man/GIT-CHECK-REF-FORMAT/1/markdown) ## NAME git-check-ref-format - Ensures that a reference name is well formed ## SYNOPSIS _git_ _check-ref-format_ [--normalize] [--[no-]allow-onelevel] [--refspec-pattern] _git_ _check-ref-format_ --branch ## DESCRIPTION Checks if a given _refname_ is acceptable, and exits with a non-zero status if it is not. A reference is used in Git to specify branches and tags. A branch head is stored in the **refs/heads **hierarchy, while a tag is stored in the **refs/tags **hierarchy of the ref namespace (typically in **$GIT_DIR/refs/heads **and **$GIT_DIR/refs/tags **directories or, as entries in file **$GIT_DIR/packed-refs **if refs are packed by **git gc**). Git imposes the following rules on how references are named: 1. They can include slash **/ **for hierarchical (directory) grouping, but no slash-separated component can begin with a dot **. **or end with the sequence **.lock**. 2. They must contain at least one **/**. This enforces the presence of a category like **heads/**, **tags/ **etc. but the actual names are not restricted. If the **--allow-onelevel **option is used, this rule is waived. 3. They cannot have two consecutive dots **.. **anywhere. 4. They cannot have ASCII control characters (i.e. bytes whose values are lower than \040, or \177 **DEL**), space, tilde **~**, caret **^**, or colon **: **anywhere. 5. They cannot have question-mark **?**, asterisk *****, or open bracket **[ **anywhere. See the **--refspec-pattern **option below for an exception to this rule. 6. They cannot begin or end with a slash **/ **or contain multiple consecutive slashes (see the **--normalize **option below for an exception to this rule). 7. They cannot end with a dot **.**. 8. They cannot contain a sequence **@{**. 9. They cannot be the single character **@**. 10. They cannot contain a **\**. These rules make it easy for shell script based tools to parse reference names, pathname expansion by the shell when a reference name is used unquoted (by mistake), and also avoid ambiguities in certain reference name expressions (see [**gitrevisions**(7)](https://www.chedong.com/phpMan.php/man/gitrevisions/7/markdown)): 1. A double-dot **.. **is often used as in **ref1..ref2**, and in some contexts this notation means **^ref1 ref2 **(i.e. not in **ref1 **and in **ref2**). 2. A tilde **~ **and caret **^ **are used to introduce the postfix _nth_ _parent_ and _peel_ _onion_ operation. 3. A colon **: **is used as in **srcref:dstref **to mean "use srcref’s value and store it in dstref" in fetch and push operations. It may also be used to select a specific object such as with _git_ _cat-file_: "git cat-file blob v1.3.3:refs.c". 4. at-open-brace **@{ **is used as a notation to access a reflog entry. With the **--branch **option, the command takes a name and checks if it can be used as a valid branch name (e.g. when creating a new branch). But be cautious when using the previous checkout syntax that may refer to a detached HEAD state. The rule **git check-ref-format** **--branch $name **implements may be stricter than what **git check-ref-format refs/heads/$name** says (e.g. a dash may appear at the beginning of a ref component, but it is explicitly forbidden at the beginning of a branch name). When run with the **--branch **option in a repository, the input is first expanded for the “previous checkout syntax” **@{-n}**. For example, **@{-1} **is a way to refer the last thing that was checked out using "git switch" or "git checkout" operation. This option should be used by porcelains to accept this syntax anywhere a branch name is expected, so they can act as if you typed the branch name. As an exception note that, the “previous checkout operation” might result in a commit object name when the N-th last thing checked out was not a branch. ## OPTIONS --[no-]allow-onelevel Controls whether one-level refnames are accepted (i.e., refnames that do not contain multiple **/**-separated components). The default is **--no-allow-onelevel**. ### --refspec-pattern Interpret as a reference name pattern for a refspec (as used with remote repositories). If this option is enabled, is allowed to contain a single *** **in the refspec (e.g., **foo/bar*/baz **or **foo/bar*baz/ **but not **foo/bar*/baz***). ### --normalize Normalize _refname_ by removing any leading slash (**/**) characters and collapsing runs of adjacent slashes between name components into a single slash. If the normalized refname is valid then print it to standard output and exit with a status of 0, otherwise exit with a non-zero status. (**--print **is a deprecated way to spell **--normalize**.) ## EXAMPLES • Print the name of the previous thing checked out: $ git check-ref-format --branch @{-1} • Determine the reference name to use for a new branch: $ ref=$(git check-ref-format --normalize "refs/heads/$newbranch")|| { echo "we do not like '$newbranch' as a branch name." >&2 ; exit 1 ; } ## GIT Part of the [**git**(1)](https://www.chedong.com/phpMan.php/man/git/1/markdown) suite Git 2.43.0 07/02/2025 [_GIT-CHECK-REF-FORMAT_(1)](https://www.chedong.com/phpMan.php/man/GIT-CHECK-REF-FORMAT/1/markdown)