Some people have, and it has often led to some frustrating and lengthy airport delays.

有些人曾拿過這樣的登機證，並因此在機場經歷了令人挫折且漫長的延後登機經驗。

So for those who are lucky enough to not know what it is and have never experienced it, what does this four letter code mean?

所以對那些有幸不用知道，也沒有經歷過的人來說，這四字編號到底有什麼意涵？

In short, the code SSSS is used on domestic and international US flights to indicate that additional security screening should be carried out.

簡單來說，SSSS 編號被用於在美國的國內與國際航班上，標記出需要進行額外安全檢查的旅客。

Airport security in many countries was beefed up significantly after the events of 2001.

在 2001 的恐怖攻擊之後， 許多國家機場的安全措施便有顯著地提升。

The US Transport Security Administration (or TSA) was formed at this time, and has increased security since with several schemes, including the Secure Flight program.

美國的運輸安全管理局 (TSA) 即是在這個時期成立的，並在之後以多項手段提升了安全層級，其中包含了安全飛行計畫。

The use of ‘SSSS’ codes has been formalized and strengthened under this, but its use is reported before then as well. 

'SSSS' 編碼的使用便在這個計畫之下開始正式設立並強化，但亦有在此之前使用過的紀錄。

According to TSA: "Secure Flight is a risk-based passenger prescreening program that enhances security

根據 TSA 的說法：「安全飛行計畫是個將乘客依風險程度預先分級的計畫，並藉由以下方式來提升安全性：

by identifying low and high-risk passengers before they arrive at the airport by matching their names against trusted traveler lists and watchlists."

藉由將旅客姓名與可信賴旅客名單與觀察名單比對，在其抵達機場前找出低度與高度風險的旅客。」

Passengers are screened for security using government databases and their travel information.

利用政府的資料庫與旅客本身的旅行資訊，旅客們會受到檢查。

This can result in several actions—of course, travel could be denied and law enforcement involved in the most severe cases,

這可能導致許多結果－當然，最嚴重的狀況下航程可能會被直接取消，執法人員並可能會因此介入，

while passengers identified as being of increased risk and requiring extra checks will have the code ‘SSSS’ printed prominently on their boarding pass.

而那些被標記為風險有所提昇並需要額外檢查的旅客，則會在登機證上被顯眼地印上 'SSSS' 標記。

Security and border agents then know to apply enhanced security checks.

安檢與邊境人員便能得知他們得進行加強安全檢查。

This is used by TSA on all US domestic flights and international flights from the US.

TSA 將這套方法使用在所有美國的國內與國際航班上。

Several factors influence the use of ‘SSSS,’ but the exact processes and decisions are not made public for obvious security reasons.

有許多因素會影響是否採用 'SSSS' 標記，但確切的流程與決策原因則理所當然地因為安全原因而沒有向大眾公開。

Being on security watchlists—including the FBI counter-terrorism watchlist—is sure to trigger the code. 

在安檢監察名單上－包括 FBI 的反恐監察名單－肯定會觸發。

Other factors might include the booking of one-way trips, booking flights last minute, or frequent recent travel.

其他的因素可能包含訂購單程票、在最後一刻才買機票，或是近期頻繁飛行。

Travel between certain airports, or to or from certain countries, will make it more likely as well.

在特定的機場間來往，或是前往或來自特定的國家，可能也會讓被標記的可能性上升。

Discrepancies between boarding pass and passport or ID information could also be to blame.

登機證與護照或身分證上的資訊不同，可能也是原因之一。

Additionally, ‘SSSS’ is sometimes assigned at random. 

另外，'SSSS' 有時也會被隨機指派。

Extra security checks are, of course, good in the overall scheme of improving security, but for individual passengers, they can be frustrating.

額外的安全檢查對於提升安全性的總體目標來說當然更好，但對於單一乘客來說，則是令人挫折的事情。

Having the code on your boarding pass will likely subject you to more checks and a longer time to clear security.

登機證上印有 SSSS 編碼可能會讓你接受更多的檢查，並使你得花更多時間才能通過安檢。

These are not usually carried out separately, but will delay you as part of the main security screening. 

這些檢查通常不會分開進行，但會在主要安全檢查時拖延到你的時間。

Extra screening might mean additional scans, a more thorough check of luggage, and taking swabs from your hands, clothes, or baggage to check for narcotics or explosives.

額外的檢查可能包括額外的掃瞄、對行李更細緻的檢查，並從你的手、衣服或行李上採樣來檢測有無毒品與爆裂物反應。

Agents are also likely to ask you questions about your travel, and you may have to wait while additional passport or identity checks are carried out. 

工作人員也可能會詢問關於你旅程的問題，而你可能得在他們進行額外的護照或身分查驗時等待。

One of the problems with ‘SSSS’ is the same travelers tend to get selected repeatedly.

'SSSS' 制度的問題是，同樣的旅客常被重複選擇到。

Fortunately, there are some ways to address this—although nothing is guaranteed, and you may still be highlighted for security reasons.

但還好你還有幾個方法能舉報這個問題－不過不保證能夠解決問題，而你仍有可能因為安全問題而被標記。

Joining the TSA PreCheck program is reported to help. 

加入 TSA PreCheck 預先安檢計畫能有所幫助。

There is also a US Homeland Security process for addressing security problems, including ‘SSSS’ codes and issues with watchlists.

美國國土安全局也有能夠舉報包含 'SSSS' 標記與觀察名單相關安全問題的管道。

The DHS Traveler Redress Inquiry Program allows travelers to report issues with boarding and airport security—issues that will be investigated and evaluated. 

國土安全局旅客補償查詢計畫能讓旅客舉報與登機及機場安檢有關的問題，而這些問題之後會被調查及評估。

Have you ever seen ‘SSSS’ on your boarding pass? What extra checks did you experience? Let us know by leaving a comment.

你有在自己的登機證上看過 'SSSS' 標記嗎？你經歷了那些額外檢查？在評論欄位中留言給我們知道吧。

In addition to our daily YouTube videos, Simple Flying publishes over 150 articles and a podcast every week.

除了我們每天都會有的 YouTube 影片外，Simple Flying 每個禮拜都會發表超過 150 篇文章，以及一篇 Podcast。

If you're looking for the latest aviation news and insights, visit simpleflying.com. Thanks for watching! And don't forget to like and subscribe before you go.

如果想知道最新的航空新聞與分析，請拜訪 simpleflying.com。感謝收看！別忘了在離開前按讚並訂閱喔。