“Type Accelerators” work like aliases for .NET types. They are intended to save typing. For example, the [ADSI] “type” really does not exist. It is a mere alias for System.DirectoryServices.DirectoryEntry. You could replace [ADSI] by [System.DirectoryServices.DirectoryEntry]:
PS> [ADSI].FullName System.DirectoryServices.DirectoryEntry PS> [System.DirectoryServices.DirectoryEntry].FullName System.DirectoryServices.DirectoryEntry
Since type accelerators are hard-coded into PowerShell, it is safe to use them. The line below dumps all the predefined type accelerators, and if you ever wanted to play with .NET types, you should pick some of these because they are important to PowerShell:
PS> [PSObject].Assembly.GetType('System.Management.Automation.TypeAccelerators')::Get
Key Value
--- -----
Alias System.Management.Automation.AliasAttribute
AllowEmptyCollection System.Management.Automation.AllowEmptyCollecti...
AllowEmptyString System.Management.Automation.AllowEmptyStringAt...
AllowNull System.Management.Automation.AllowNullAttribute
ArgumentCompleter System.Management.Automation.ArgumentCompleterA...
array System.Array
bool System.Boolean
byte System.Byte
char System.Char
CmdletBinding System.Management.Automation.CmdletBindingAttri...
datetime System.DateTime
decimal System.Decimal
double System.Double
DscResource System.Management.Automation.DscResourceAttribute
float System.Single
single System.Single
guid System.Guid
hashtable System.Collections.Hashtable
int System.Int32
int32 System.Int32
int16 System.Int16
long System.Int64
int64 System.Int64
ciminstance Microsoft.Management.Infrastructure.CimInstance
cimclass Microsoft.Management.Infrastructure.CimClass
cimtype Microsoft.Management.Infrastructure.CimType
cimconverter Microsoft.Management.Infrastructure.CimConverter
IPEndpoint System.Net.IPEndPoint
NullString System.Management.Automation.Language.NullString
OutputType System.Management.Automation.OutputTypeAttribute
ObjectSecurity System.Security.AccessControl.ObjectSecurity
Parameter System.Management.Automation.ParameterAttribute
PhysicalAddress System.Net.NetworkInformation.PhysicalAddress
pscredential System.Management.Automation.PSCredential
PSDefaultValue System.Management.Automation.PSDefaultValueAttr...
pslistmodifier System.Management.Automation.PSListModifier
psobject System.Management.Automation.PSObject
pscustomobject System.Management.Automation.PSObject
psprimitivedictionary System.Management.Automation.PSPrimitiveDictionary
ref System.Management.Automation.PSReference
PSTypeNameAttribute System.Management.Automation.PSTypeNameAttribute
regex System.Text.RegularExpressions.Regex
DscProperty System.Management.Automation.DscPropertyAttribute
sbyte System.SByte
string System.String
SupportsWildcards System.Management.Automation.SupportsWildcardsA...
switch System.Management.Automation.SwitchParameter
cultureinfo System.Globalization.CultureInfo
bigint System.Numerics.BigInteger
securestring System.Security.SecureString
timespan System.TimeSpan
uint16 System.UInt16
uint32 System.UInt32
uint64 System.UInt64
uri System.Uri
ValidateCount System.Management.Automation.ValidateCountAttri...
ValidateDrive System.Management.Automation.ValidateDriveAttri...
ValidateLength System.Management.Automation.ValidateLengthAttr...
ValidateNotNull System.Management.Automation.ValidateNotNullAtt...
ValidateNotNullOrEmpty System.Management.Automation.ValidateNotNullOrE...
ValidatePattern System.Management.Automation.ValidatePatternAtt...
ValidateRange System.Management.Automation.ValidateRangeAttri...
ValidateScript System.Management.Automation.ValidateScriptAttr...
ValidateSet System.Management.Automation.ValidateSetAttribute
ValidateTrustedData System.Management.Automation.ValidateTrustedDat...
ValidateUserDrive System.Management.Automation.ValidateUserDriveA...
version System.Version
void System.Void
ipaddress System.Net.IPAddress
DscLocalConfigurationManager System.Management.Automation.DscLocalConfigurat...
WildcardPattern System.Management.Automation.WildcardPattern
X509Certificate System.Security.Cryptography.X509Certificates.X...
X500DistinguishedName System.Security.Cryptography.X509Certificates.X...
xml System.Xml.XmlDocument
CimSession Microsoft.Management.Infrastructure.CimSession
adsi System.DirectoryServices.DirectoryEntry
adsisearcher System.DirectoryServices.DirectorySearcher
wmiclass System.Management.ManagementClass
wmi System.Management.ManagementObject
wmisearcher System.Management.ManagementObjectSearcher
mailaddress System.Net.Mail.MailAddress
scriptblock System.Management.Automation.ScriptBlock
psvariable System.Management.Automation.PSVariable
type System.Type
psmoduleinfo System.Management.Automation.PSModuleInfo
powershell System.Management.Automation.PowerShell
runspacefactory System.Management.Automation.Runspaces.Runspace...
runspace System.Management.Automation.Runspaces.Runspace
initialsessionstate System.Management.Automation.Runspaces.InitialS...
psscriptmethod System.Management.Automation.PSScriptMethod
psscriptproperty System.Management.Automation.PSScriptProperty
psnoteproperty System.Management.Automation.PSNoteProperty
psaliasproperty System.Management.Automation.PSAliasProperty
psvariableproperty System.Management.Automation.PSVariableProperty
