When I was learning Dynamics CRM , I saved this information in my One Note. I don’t exactly remember from where i got it but this is some valuable information about field data type and its formats, now sharing it with you.
Types of fields
As you use fields in your customization the first thing you need to understand are the types of fields you can create and edit and some of the system fields an entity may have. It is useful to organize these into groups based on the type of data you want to capture. The following table summarizes these field types.
Text Data
Single Line of Text
Up to 4000 characters of text can be in this field. You can set a maximum length to less than this. This field has several format options that will change the presentation of the text. These options are Email, Text, Text Area, URL and Ticker Symbol and Phone.
Multiple Lines of Text
Up to 1,048,576 characters of text can be in this field. You can set a maximum length to less than this. When you add this field to the form you can specify the size of the field.
Categorization Data
Option Set
This field provides a set of options. Each option has a number value and label. When added to a form this field uses a select control and only one option can be selected. When displayed in Advanced Find, you can use a picklist control to select multiple options to include in your search criteria. You may define a single global option set and configure multiple option set fields to use that single set of options.
Two Option
This field provides two options. Each option has a number value of 0 or 1 corresponding to a false or true value. Each option also has a label so that true or false values can be represented as “Yes” and “No”, “Hot” and “Cold”, “On” and “Off” or any pair of labels you want to display. Two option fields don’t provide format options at the field level. But when you add one to the form you can choose to display them as radio buttons, a check box, or a select list.
Status
A system field that has options that generally correspond to active and inactive status. Some system attributes have additional options, but all custom attributes have only Active and Inactive status options.
Status Reason
A system field that has options that provide additional detail about the Status field. Each option is associated with one of the available Status options. You can add and edit the options.
Quantification Data
Whole Number
Integers with a value between 2,147,483,648 and 2,147,483,647 can be in this field. You can restrict the maximum or minimum values in this range. This field has format options None, Duration, Time Zone, and Language that change depending on how the field is presented.
Floating Point Number
Up to 5 decimal points of precision can be used for values between -100,000,000,000 and 100,000,000,000 can be in this field. You can specify the level of precision and the maximum and minimum values.
Decimal Number
Up to 10 decimal points of precision can be used for values between -100,000,000,000 and 100,000,000,000 can be in this field. You can specify the level of precision and the maximum and minimum values.
Currency
Monetary values between 922,337,203,685,477 and 922,337,203,685,477 can be in this field. You can set a level of precision or choose to base the precision on a specific currency or a single standard precision used by the organization.
Time Data
Date and Time
This field has format options to display Date Only or Date and Time.
Image Data
Image
Each entity that supports images can have one image field. When an entity has an image field, it can be configured to display the image for the record in the application
Referential Data
Lookup
A field that allows setting a reference to a single record of a specific type of entity. Some system lookup fields behave differently.Owner A system lookup field that references the user or team that is assigned a user or team owned entity record.
Id Unique Identifier A system field stores a globally unique identifier (GUID) value for each record.
Single line of text format options
The text provides a mailto link to open the user’s email application.
Text
This option simply displays text.
Text Area
This format option can be used to display multiple lines of text. But with a limit of 4000 characters, the Multiple Lines of Text field is a better choice if large amounts of text are expected.
URL
The text provides a hyperlink to open the page specified. Any text that does not begin with a valid protocol will have “http://” prepended to it. Only HTTP, HTTPS, FTP , FTPS, ONENOTE and TEL protocols are allowed in this field.
Ticker Symbol
For most languages, the text will be enabled as a link to open the MSN Money website to show details about the stock price represented by the ticker symbol. For certain East Asian languages the window will open Bing search results for the ticker symbol.
Phone
In the web application, fields will be click enabled to initiate calls using either Skype or Lync if a client for either is installed on your computer. The telephony provider choice is at the bottom of the General tab of System Settings. For Microsoft Dynamics CRM for tablets, Skype is the only available telephony provider.
Whole number format options
Duration
This format option can be used to display a list of duration options. But the data stored in the database is always a number of minutes. The field looks like a drop-down list and provides suggested options like 1 minute, 15 minutes, 30 minutes all the way up to 3 days. People can choose these options. However, people can also just type in a number of minutes and it resolves to that period of time. For example, type in 60 and it resolves to 1 hour. Or they can enter “1 hour” or “2 days” and it will resolve to display that time. The duration must be entered in the following format: “x minutes”, “x hours” or “x days”. Hours and days can also be entered using decimals, for example, “x.x hours” or “x.x days”.
Time Zone
This option displays a select list of time zones such as (GMT-12:00) International Date Line West and (GMT-08:00) Pacific Time (US & Canada). Each of these zones is stored as a number.
This Information helped me a lot back then i wish it help you too.