Regular expression for Culture Code

/^[a-z]{2,3}(?:-[A-Z]{2,3}(?:-[a-zA-Z]{4})?)?$/

Here is how it works

^       <- Starts with
[a-z]   <- From a to z (lower-case)
{2,3}   <- Repeated at least 2 times, at most 3
(?:     <- Non capturing group
   -        <- The "-" character
   [A-Z]     <- From a to z (upper-case)
   {2,3}     <- Repeated at least 2 times, at most 3
   (?:       <- Non capturing group
       -         <- The "-" character
       [a-zA-Z]  <- from a to Z (case insensitive)
       {4}      <- Repeated 4 times
   )         <- End of the group
   ?         <- Facultative
 )       <- End of the group
 ?       <- Facultative
 $       <- Ends here

SPField.Type property & FEW ENUMERATION & LINKS

SPField.Type property :   https://msdn.microsoft.com/en-us/library/microsoft.sharepoint.spfield.type.aspx

SPFieldType enumeration:  https://msdn.microsoft.com/en-us/library/microsoft.sharepoint.spfieldtype.aspx  

SPRichTextMode enumeration:  https://msdn.microsoft.com/en-us/library/microsoft.sharepoint.sprichtextmode.aspx

Search Enumeration in first link for All type of enumeration. 

Change Column Type in SharePoint List using PowerShell

param(
[String]$ConfigPath = $(throw "Configuration object required to execute script."),
[String]$LocalesPath = $(throw "Settings object required to execute script.")
)
#################################################################################

$configSettings = New-Object -TypeName XML
$configSettings.Load($ConfigPath)

$localeSettings = New-Object -TypeName XML
$localeSettings.Load($LocalesPath)


##Script to run : .\Update-EventContentType.ps1 -ConfigPath "Full Path Configuration File" -LocalesPath "Full Path of Settings File"


function Update-FieldVideo {
    param(
   [string] $SiteUrl
    )
$site = Get-SPSite $SiteUrl
$web = $site.RootWeb

        $ct = $site.RootWeb.ContentTypes["Intranet Video News"]
write-Host "content Type Found"  -foregroundcolor green
write-Host "Update Field Display Name Start"  -foregroundcolor green

        $location = $ct.FieldLinks["IntranetVideoText2"]
        $location.Type = [Microsoft.SharePoint.SPFieldType]::Note

$desc = $ct.FieldLinks["IntranetVideoText1"]
        $desc.Type = [Microsoft.SharePoint.SPFieldType]::Note //FOR THIS PART CHECK ANOTHER ARTICLE FOR FIELD TYPE IN POWERSHELL

$ct.Update($true)

write-Host "Update Field Display Name End"  -foregroundcolor green
}


foreach ($sc in $configSettings.Config.SiteCollections.ChildNodes) {

    if($sc.IsRootHNSC -ne "true"){
        $SiteUrl = "{0}/{1}/{2}" -f $localeSettings.Settings.HNSC_HostHeader,$localeSettings.Settings.HNSC_ManagedPath,$sc.SiteUrl
#Update-FieldList -SiteUrl $SiteUrl
#Update-FieldOrder -SiteUrl $SiteUrl
#Update-contentTypeList -SiteUrl $SiteUrl
Update-FieldVideo -SiteUrl $SiteUrl
       }
}

SharePoint Field TYPE for Elements.xml

Single Line of Text:
field id=”{FDDC4E38-25E0-4FD9-92E7-D17F34A5AB12}” description=”My Content ID of Item” staticname=”ContentID” name=”ContentID” displayname=”ContentID” type=”Text” group=”Sample Site Columns” sourceid=”http://schemas.microsoft.com/sharepoint/v3″

Number:
Field ID=”{13b3652a-d543-465d-91cb-a9d625637855}” StaticName=”Read_Times” Name =”Read_Times” DisplayName =”Read_Times” Description=”Read Time count of Item” Type=”Number” Group =”Sample Site Columns” SourceID =”http://schemas.microsoft.com/sharepoint/v3″

Date Time:
Field ID=”{d076e4d5-c785-4c04-8b56-c1f021721749}” StaticName=”CreateDate” Name=”CreateDate” DisplayName=”Create_Date” Description=”Create Date of Item” Group=”Sample Site Columns” Type=”DateTime” Format=”DateOnly” SourceID=”http://schemas.microsoft.com/sharepoint/v3/fields”

Multiple lines of text:
Field ID=”{2ae59f08-0fb0-4a9c-8a31-a180161b1029}” StaticName=”PublisherDescription” Name=”PublisherDescription” Description=”Publisher Description of Item” DisplayName=”Publisher_Description” Type=”Note” RichText=”FALSE” NumLines=”6″ Group=”Sample Site Columns” SourceID=”http://schemas.microsoft.com/sharepoint/v3/fields”

Rich Text HTML:
Field ID=”{13cd0291-df15-4278-9894-630913e4d2b9}” StaticName=”AccrediterDescription” Name=”AccrediterDescription” DisplayName=”Accrediter_Description” Description=”Accrediter Description of Item” Type=”Note” NumLines=”6″ RichText=”TRUE” RichTextMode=”FullHtml” Group=”Sample Site Columns” SourceID=”http://schemas.microsoft.com/sharepoint/v3/fields”

Publishing HTML:
Field ID=”{E2CC0231-FA6C-4F90-839C-118C304DFCF1}” StaticName=”PMediaDescription” Name=”PMediaDescription” DisplayName=”MediaDescription” Type=”HTML” RichText=”TRUE” RichTextMode=”ThemeHtml” Group=”Site Columns” SourceID=”http://schemas.microsoft.com/sharepoint/v3″ UnlimitedLengthInDocumentLibrary =”TRUE”

Publishing Image:
field id=”{148e8191-afe7-4422-b1d1-7202eda667f1}” description=”Image 1 link of Item” staticname=”PImageID1″ name=”PImageID1″ displayname=”Image_ID1″ type=”Image” group=”My Site Columns” sourceid=”http://schemas.microsoft.com/sharepoint/v3″ richtext=”TRUE” richtextmode=”ThemeHtml”>

HyperLink & Image:
Field ID=”{635a2031-2088-4413-b54e-d2af5daf08bf}” StaticName=”ImageAuthor” Name=”ImageAuthor” DisplayName=”Image_Author” Description=”Author Image” Type=”URL” Format=”Image” Group=”Sample Site Columns” SourceID=”http://schemas.microsoft.com/sharepoint/v3/fields”

YES/No Boolean:
<Field ID=”{11018312-58f9-4eb0-867d-71298f82d98d}” Name=”isActive” StaticName=”isActive” DisplayName=”isActive” Description=”Select if Item is Active” Group=”Sample Site Columns” SourceID=”http://schemas.microsoft.com/sharepoint/v3&#8243; Type=”Boolean”&gt;
<default>0</default>
</FIELD>

CHOICES:
<Field ID=”{67f8faa4-e3ee-44bf-a3b4-6e7fc9c6b9fe}” Name=”Market” StaticName=”Market” DisplayName=”Market” Description=”Market of the Country” Group=”Sample Site Columns” SourceID=”http://schemas.microsoft.com/sharepoint/v3&#8243; Type=”Choice”&gt;
<choices>
choice>Gold</choice
</choices>
</FIELD>

MultiSelect:
<Field Type=”MultiChoice” DisplayName=”Labels_Selected” FillInChoice=”FALSE” Group=”Sample Site Columns” ID=”{2fdf0ba7-0052-4e9f-80f6-e7669ac4ae4f}” SourceID=”http://schemas.microsoft.com/sharepoint/v3&#8243; StaticName=”LabelsSelected” Name=”LabelsSelected”&gt;
</FIELD>

Lookup Columns:
Field Type=”Lookup” ID=”{FE45AC76-C0E2-46C8-A047-E8C43C10315C}” Name=”LU_Country” StaticName=”LU_Country” DisplayName=”LU_Country” Required=”FALSE” List=”Lists/Region Country Master” ShowField=”RollOutCountry” UnlimitedLengthInDocumentLibrary=”FALSE” SourceID=”http://schemas.microsoft.com/sharepoint/v3/fields&#8221; Group=”Sample Site Columns”

Multi Lookup Columns:
Field Type=”LookupMulti” Mult=”TRUE” ID=”{85062ACF-315B-460A-B756-2230A5FE082F}” Name=”LU_Language” StaticName=”LU_Language” DisplayName=”LU_Language” Required=”FALSE” List=”Lists/Language Master” ShowField=”Title” UnlimitedLengthInDocumentLibrary=”FALSE” SourceID=”http://schemas.microsoft.com/sharepoint/v3/fields&#8221; Group=”Sample Site Columns”

Lookup with Additional Field Lookup column:
Field Type=”Lookup” ID=”{9AA2985D-AA17-4EA2-9556-9B0E112A64F6}” Name=”LU_ApplicationType” StaticName=”LU_ApplicationType” DisplayName=”LU_ApplicationType” Required=”FALSE” List=”Lists/Application Type” ShowField=”ApplicationType” UnlimitedLengthInDocumentLibrary=”FALSE” SourceID=”http://schemas.microsoft.com/sharepoint/v3/fields&#8221; Group=”Sample Site Columns”

Field Type=”Lookup” ID=”{668D51C4-804D-43E7-8211-950AE3BCD9A3}” Name=”LU_ApplicationType_ID” StaticName=”LU_ApplicationType_ID” DisplayName=”LU_ApplicationType_ID” List=”Lists/Application Type” ShowField=”ApplicationTypeID” FieldRef=”9AA2985D-AA17-4EA2-9556-9B0E112A64F6″ ReadOnly=”TRUE” UnlimitedLengthInDocumentLibrary=”FALSE” SourceID=”http://schemas.microsoft.com/sharepoint/v3/fields&#8221; Group=”Sample Site Columns”

User column
<Field ID=”{080FF274-4FAB-43c9-9710-78F3A76925DC}” Type=”User”DisplayName=”My User” StaticName=”MyUser” Name=”User” Required=”TRUE” UserSelectionMode=”PeopleOnly” ShowField=”Name” ></Field>