Setting this to `"false"` hides all issues with `Mixed` types in Psalm’s output. If not given, this defaults to `"false"` when `errorLevel` is 3 or higher, and `"true"` when the error level is 1 or 2.
\(Deprecated\) Setting `totallyTyped` to `"true"` is equivalent to setting `errorLevel` to `"1"`. Setting `totallyTyped` to `"false"` is equivalent to setting `errorLevel` to `"2"` and `reportMixedIssues` to `"false"`
If not using all docblock types, you can still use docblock property types. Defaults to `false` (though only relevant if `useDocblockTypes` is `false`.
The PHPDoc `@method` annotation normally only applies to classes with a `__call` method. Setting this to `true` allows you to use the `@method` annotation to override inherited method return types. Defaults to `false`.
Some like to use [`assert`](http://php.net/manual/en/function.assert.php) for type checks. If `true`, Psalm will process assertions inside `assert` calls. Defaults to `true`.
Setting this to `false` means that any function calls will cause Psalm to forget anything it knew about object properties within the scope of the function it's currently analysing. This duplicates functionality that Hack has. Defaults to `true`.
Allows you to specify whether or not to use the typed iterator docblock format supported by PHP Storm e.g. `ArrayIterator|string[]`, which Psalm transforms to `ArrayIterator<string>`. Defaults to `false`.
When `true`, strings can be coerced to [`class-string`](../annotating_code/templated_annotations.md#param-class-stringt), with Psalm emitting a `TypeCoercion` issue. If disabled, that issue changes to a more serious one. Defaults to `false`.
When `true`, strings can be used as classes, meaning `$some_string::someMethod()` is allowed. If `false`, only class constant strings (of the form `Foo\Bar::class`) can stand in for classes, otherwise an `InvalidStringClass` issue is emitted. Defaults to `false`.
When `true`, the results of method calls without arguments passed arguments are remembered between repeated calls of that method on a given object. Defaults to `false`.
When `true`, constants defined in a function in a file are assumed to be available when requiring that file, and not just when calling that function. Defaults to `false` (i.e. constants defined in functions will *only* be available for use when that function is called)
Occasionally a param default will not match up with the docblock type. By default, Psalm emits an issue. Setting this flag to `true` causes it to expand the param type to include the param default. Defaults to `false`.
When `true`, Psalm will check that the developer has supplied `@throws` docblocks for every exception thrown in a given function or method. Defaults to `false`.
When `true`, Psalm ignores possibly-false issues stemming from return values of internal functions (like `preg_split`) that may return false, but do so rarely). Defaults to `true`.
When `true`, Psalm ignores possibly-null issues stemming from return values of internal array functions (like `current`) that may return null, but do so rarely. Defaults to `true`.
When `true`, Psalm will attempt to find all unused variables, the equivalent of running with `--find-unused-variables`. Defaults to `false`.
#### findUnusedCode
```xml
<psalm
findUnusedCode="[bool]"
>
```
When `true`, Psalm will attempt to find all unused code (including unused variables), the equivalent of running with `--find-unused-code`. Defaults to `false`.
When `true`, Psalm will complain when referencing an explicit string offset on an array e.g. `$arr['foo']` without a user first asserting that it exists (either via an `isset` check or via an object-like array). Defaults to `false`.
Set the php version psalm should assume when checking and/or fixing the project. If this attribute is not set, psalm uses the declaration in `composer.json` if one is present. It will check against the earliest version of PHP that satisfies the declared `php` dependency
This can be overridden on the command-line using the `--php-version=` flag which takes the highest precedence over both the `phpVersion` setting and the version derived from `composer.json`.
if your application registers one or more custom autoloaders, and/or declares universal constants/functions, this autoloader script will be executed by Psalm before scanning starts. Psalm always registers composer's autoloader by default.
The directory used to store Psalm's cache data - if you specify one (and it does not already exist), its parent directory must already exist, otherwise Psalm will throw an error.
Allows you to hard-code a serializer for Psalm to use when caching data. By default, Psalm uses `ext-igbinary`*if* the version is greater or equal to 2.0.5, otherwise it defaults to PHP's built-in serializer.
Contains a list of all the directories that Psalm should inspect. You can also specify a set of files and folders to ignore with the `<ignoreFiles>` directive, e.g.
Optional. If you don't want Psalm to complain about every single issue it finds, the issueHandler tag allows you to configure that. [Dealing with code issues](dealing_with_code_issues.md) tells you more.
Optional. Do you use mock classes in your tests? If you want Psalm to ignore them when checking files, include a fully-qualified path to the class with `<class name="Your\Namespace\ClassName" />`
Optional. If your codebase uses classes and functions that are not visible to Psalm via reflection (e.g. if there are internal packages that your codebase relies on that are not available on the machine running Psalm), you can use stub files. Used by PhpStorm (a popular IDE) and others, stubs provide a description of classes and functions without the implementations. You can find a list of stubs for common classes [here](https://github.com/JetBrains/phpstorm-stubs). List out each file with `<file name="path/to/file.php" />`.
Optional. A list of exceptions to not report for `checkForThrowsDocblock` or `checkForThrowsInGlobalScope`. If an exception has `onlyGlobalScope` set to `true`, only `checkForThrowsInGlobalScope` is ignored for that exception, e.g.
