SMS Glossary

As with any new and exciting tool, Postscript and SMS marketing have some key terms that we recommend you familiarize yourself with as you navigate and use the app and this help center. 

We've listed out some of the most important terms below along with bite-sized definitions. Let us know if we missed any by selecting the purple chat icon in the lower-right corner of this page!

A - I

ADA ADA compliance refers to the Americans with Disabilities Act Standards for Accessible Design. These standards require that companies offer and maintain websites and content that people with disabilities can easily use and access. For more details on ADA compliance, check out the ADA's website.
Automation (Legacy) A message or series of messages that are triggered by an event (e.g., a subscriber opts-in to SMS, a shopper abandons a cart, an order is delivered, etc.) and are sent automatically. Learn how to create a legacy automation.
Automation Flow An automation flow is similar to a legacy automation, but is powered by Flow Builder so flows can be crafted using Flow Builder's robust toolset. Learn how to create an automation flow.
BFCM Black Friday and Cyber Monday. The busiest time of the year for merchants.
Billing Threshold A set amount of spend that a shop must reach before they will see a usage charge to their payment on file. Learn more about billing thresholds here.
Call to Action (CTA)

Copy that asks users to take an action. For example, in the case of texting a keyword to your short code to opt-in to your text messaging campaign, the CTA might be Text MOBILE to 662266 to subscribe to sale alerts and discounts! 

Also refers to the action part of your campaign or automation message, such as Shop Now or Place Your Order Today!

Campaign (Legacy) A message or series of messages meant to deliver timely communications (e.g., promotions, product launches, content shares, etc.) to your subscribers. Campaigns are not triggered by an event but rather scheduled and sent by the brand. Learn how to create a campaign.
Campaign Flow A campaign flow is similar to a legacy campaign, but is powered by Flow Builder so flows can be crafted using Flow Builder's robust toolset. Learn how to create a campaign flow.
Carrier Fees Carrier fees are small surcharges that mobile carriers apply to both incoming and sent messages. Carrier fees will differ based on the type of messages sent (i.e., SMS vs. MMS) and the phone number sending the message (i.e., a toll-free number or a short code). Learn more about carrier fees here.
Click-Through Rate (CTR)

Percentage of clicks the link(s) included in a message received. We calculate the click-through rate as (# of clicks) / (# of messages opened) * 100


The Cellular Telecommunications Industry Association represents the wireless communications industry in the United States and sets forth messaging principles and best practices enforced by the carriers.

Earnings Per Message (EPM) We calculate earnings per message as (total revenue) / (# of messages delivered) * 100
Emoji A digital image or icon used to express an idea, emotion, etc. They're a great way to insert personality in your messages 😉 🎉 ✨ 💕
Flow Builder Postscript’s intuitive drag-and-drop interface that makes it easy to build, visualize, and manage SMS flows. You can create anything from simple campaign sends to complex automation flows with multiple branches.
GIF An animated image. You can include one GIF in a campaign message, automation message, or keyword reply.

J - P


A word a subscriber can text to your short code or toll-free number to opt-in to SMS messages from your brand. You can also use keywords to create interactive experiences for your subscribers.

List Growth The act of collecting SMS subscribers. You have several options when it comes to list growth, so you can choose the ones that work best for your brand.
Message Tag A dynamic placeholder you can use in messages that, when sent, populate with information unique to a specific subscriber or product. For example, {first_name} is a message tag that will appear as the first name of the individual subscriber.

A text message that includes an animated GIF or image. Learn more about the differences between SMS and MMS here.

Network Carriers Wireless telecommunication carriers such as Verizon, AT&T, T-Mobile, etc.
Opt-In The act of subscribing to SMS marketing messages from a shop.
Opt-Out The act of unsubscribing to SMS marketing messages from a shop.

A modal that allows shoppers to opt-in to SMS text messaging from a shop, usually in exchange for a discount or early access to product releases. Available for desktop and mobile devices.

Q - Z

Quiet Hours Specific times during the day when you should avoid sending text messages to your subscribers.
Safe Send

Prevents a text message (as part of a campaign) from sending to a subscriber who received a text from your shop within the last 16 hours.

Segment A subset of subscribers who fit specific criteria (e.g., number of orders = 0, total spend = $100+, etc.)
SHAFT SHAFT regulations protect consumers by prohibiting brands from sending content containing sex, hate, alcohol, firearms, or tobacco (CBD--included) to inappropriate audiences.
Short Code A 5- or 6-digit phone number brands can use to send SMS and MMS to a subscriber's mobile device. Learn more about short codes here.

A standard, image/GIF-free text message that can include emojis. Learn more about the differences between SMS and MMS here.

Subscriber An individual who has signed up for (aka opted-in to) SMS messages from a brand using their phone number.
Subscriber Event Split*

Subscriber Event Split is available in Flow Builder for both campaign and automation flows. This action allows you to build unique branches based on subscriber actions-- like responding to a message or using a coupon.

*Subscriber Event Split is formerly known as Wait for Event Branching


The Telephone Consumer Protection Act (TCPA) put forth regulations that dictate how companies can use SMS and MMS text messaging services to reach out to their consumers.

Toll-Free Number (TFN) A 10-digit number starting with (8XX) that a shop can use to send SMS and MMS messages to a subscriber's mobile device. Learn more about toll-free numbers here.
Trigger Event Split

Trigger Event Splits are available in Flow Builder-- specifically for automation flows. They allow you to build unique branches determined by subscriber and product conditions.

For example, if you wanted to create one automation flow that targets subscribers differently based on the dollar amount in their abandoned cart, you may consider using trigger event splits.

Wait for Event Branching See definition of Subscriber Event Split
Waking Hours Specific times during the day when you are encouraged to send messages to your subscribers. View recommended waking hours here.

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