Question

what are the rules to enter field name

Answer 1

ArcGIS General Rules For Column (or Field) Names in Excel

Field names need to start with a letter.Field names should only include alphanumeric characters or underscores.None of these: `~@#$%^&*()-+=| ,<>?/ {}.!'[]:;No spaces (That includes before the field name, in the middle, or after it.Field names will be cut off after 64 characters.

Answer 2

Field names have to be unique.A very few field names are reserved. If you try to use one of these names, Foswiki will automatically append an underscore to the name when the form is used.You can space out the title of the field, and it will still find the topic e.g. Aeroplane Manufacturers is equivalent to AeroplaneManufacturers.If a label field has no name, it will notbe shown when the form is viewed, only when it is edited.Field names can in theory include any text, but you should stick to alphanumeric characters. If you want to use a non-wikiname for a select, checkbox or radio field, and want to get the values from another topic, you can use [[...]] links. This notation can also be used when referencing another topic to obtain field values, but a name other than the topic name is required as the name of the field.Leading and trailing spaces are notsignificant.