It alters a quota definition, for a particular account. It is available at account or collection level. At deployment level, the quota definitions cannot be changed.
Namespace:  Microsoft.TeamFoundation.Framework.Server
Assembly:  Microsoft.TeamFoundation.Framework.Server (in Microsoft.TeamFoundation.Framework.Server.dll)
Syntax
'Declaration
Public Sub AlterQuotaDefinition ( _
    requestContext As TeamFoundationRequestContext, _
    quotaName As String, _
    softCap As Nullable(Of Integer), _
    hardCap As Nullable(Of Integer), _
    isEnabled As Nullable(Of Boolean) _
)
public void AlterQuotaDefinition(
    TeamFoundationRequestContext requestContext,
    string quotaName,
    Nullable<int> softCap,
    Nullable<int> hardCap,
    Nullable<bool> isEnabled
)
public:
void AlterQuotaDefinition(
    TeamFoundationRequestContext^ requestContext, 
    String^ quotaName, 
    Nullable<int> softCap, 
    Nullable<int> hardCap, 
    Nullable<bool> isEnabled
)
member AlterQuotaDefinition : 
        requestContext:TeamFoundationRequestContext * 
        quotaName:string * 
        softCap:Nullable<int> * 
        hardCap:Nullable<int> * 
        isEnabled:Nullable<bool> -> unit
public function AlterQuotaDefinition(
    requestContext : TeamFoundationRequestContext, 
    quotaName : String, 
    softCap : Nullable<int>, 
    hardCap : Nullable<int>, 
    isEnabled : Nullable<boolean>
)
Parameters
- requestContext
 Type: Microsoft.TeamFoundation.Framework.Server.TeamFoundationRequestContext
- quotaName
 Type: System.String
- softCap
 Type: System.Nullable<Int32>
- hardCap
 Type: System.Nullable<Int32>
- isEnabled
 Type: System.Nullable<Boolean>
.NET Framework Security
- Full trust for the immediate caller. This member cannot be used by partially trusted code. For more information, see Using Libraries from Partially Trusted Code.