I have created a WCF Service (Ajax-enabled).
With [Serializable] attribute decorated to my class, the output looks as below:
<_x003C_FirstName_x003E_k__BackingField>ABC</_x003C_FirstName_x003E_k__BackingField> <_x003C_HomePhone_x003E_k__BackingField>1234567890</_x003C_HomePhone_x003E_k__BackingField> <_x003C_LastName_x003E_k__BackingField>PQR</_x003C_LastName_x003E_k__BackingField> <_x003C_MailAddress2_x003E_k__BackingField/>
And by removing the [Serializable] attribute to my class, the output does not render any data as below:
<FirstName i:nil="true"/<HomePhone i:nil="true"/<LastName i:nil="true"/ <MailAddress1 i:nil="true"/